#include <bits/stdc++.h>
static char buf[1000000],*paa=buf,*pd=buf;
static char buf2[1000000],*pp=buf2;
#define getchar() paa==pd&&(pd=(paa=buf)+fread(buf,1,1000000,stdin),paa==pd)?EOF:*paa++
inline void pc(char ch){
	if(pp-buf2==1000000) fwrite(buf2,1,1000000,stdout),pp=buf2;
	*pp++=ch;
}
inline void pcc(){
	fwrite(buf2,1,pp-buf2,stdout);
	pp=buf2;
}
inline int read(void) {
	int w=1;
	register int x(0);register char c(getchar());
	while(c<'0'||c>'9') {if(c=='-') w=-1;c=getchar();}
	while(c>='0'&&c<='9') x=(x<<1)+(x<<3)+(c^48),c=getchar();
	return w*x;
}
#pragma GCC optimize("Ofast,no-stack-protector")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,avx2,tune=native")
int rev[4000009],p[1000009],iv[1000009];
const int g=3,MOD=998244353,MAX=1000005;
struct complex{
    double x,y;
    complex(double x=0,double y=0):x(x),y(y){}
    inline complex operator+(complex b) {
        return complex(x+b.x,y+b.y);
    }
    inline complex operator-(complex b) {
        return complex(x-b.x,y-b.y);
    }
    inline complex operator*(complex b) {
        complex res;
        res.x=x*b.x-y*b.y;
        res.y=x*b.y+y*b.x;
        return res;
    }
};
inline int pw(int a,int b) {
    int as=1;
    while(b) {
        if(b&1) as=1ll*as*a%MOD;
        a=1ll*a*a%MOD;
        b>>=1;
    }
    return as;
}
inline int ni(int a) {
    return pw(a,MOD-2);
}
void binom(void) {
    p[0]=1;
    for(int i=1;i<=MAX;i++) p[i]=1ll*p[i-1]*i%MOD;
    iv[MAX]=ni(p[MAX]);
    for(int i=MAX-1;i>=0;i--) iv[i]=1ll*iv[i+1]*(i+1)%MOD;
}
struct poly{
    std::vector<int> f;
    inline int sz(void) {
        return f.size()-1;
    }
    inline void NTT(std::vector<int>& a,int t,int lim,int g) {
        for(int i=1;i<=lim;i++) if(i<rev[i]) std::swap(a[i],a[rev[i]]);
        int rt,w,x,y;
        for(int mid=1;mid<lim;mid<<=1) {
            int r=mid<<1;
            rt=pw(g,(MOD-1)/r);
            if(t==-1) rt=ni(rt);
            for(int j=0;j<lim;j+=r) {
                w=1;
                for(int k=0;k<mid;k++) {
                    x=a[j|k];
                    y=1ll*w*a[j|k|mid]%MOD;
                    a[j|k]=((x+y>=MOD)?(x+y-MOD):(x+y));
                    a[j|k|mid]=((x-y<0)?(x-y+MOD):(x-y));
                    w=1ll*w*rt%MOD;
                }
            }
        }
        if(t==1) return;
        int qq=ni(lim);
        for(int i=0;i<=lim;i++) a[i]=1ll*a[i]*qq%MOD;
    }
/*  inline poly operator*(poly a) {
        int n=std::max(f.size()-1,a.f.size()-1),lim=1,x=-1;
        while(lim<=(n<<1)) {
            lim<<=1;
            x++;
        }
        for(int i=1;i<=lim;i++) rev[i]=(rev[i>>1]>>1)|((i&1)<<x);
        std::vector<complex> tp;tp.resize(lim+1);
        for(int i=0;i<f.size();i++) tp[i].x=f[i];
        for(int i=0;i<a.f.size();i++) tp[i].y=a.f[i];   
        FFT(tp,1,lim);
        for(int i=0;i<=lim;i++) tp[i]=tp[i]*tp[i];
        FFT(tp,-1,lim);
        poly c;c.f.resize(f.size()-1+a.f.size());
        for(int i=0;i<f.size()-1+a.f.size();i++) {
            c.f[i]=tp[i].y/2+0.5;
            c.f[i]%=MOD;
        }
        return c;
    }*/
    inline poly operator+(poly a) {
        int n=std::max(f.size()-1,a.f.size()-1);
        a.f.resize(n+1);
        for(int i=0;i<f.size();i++) {
            a.f[i]=(a.f[i]+f[i])>=MOD?(a.f[i]+f[i])-MOD:(a.f[i]+f[i]); 
        }
        return a;
    }
    inline poly operator+(int x) {
        poly a;a.f=f;a.f[0]=(a.f[0]+x>=MOD)?(a.f[0]+x-MOD):(a.f[0]+x); 
        return a;
    }
    inline poly operator-(poly a) {
        int n=std::max(f.size()-1,a.f.size()-1);
        a.f.resize(n+1);
        for(int i=0;i<f.size();i++) {
            a.f[i]=(f[i]-a.f[i])<0?(f[i]-a.f[i])+MOD:(f[i]-a.f[i]); 
        }
        for(int i=f.size();i<=n;i++) {
            a.f[i]=(a.f[i]==0?0:(MOD-a.f[i]));
        }
        return a;
    }
    inline poly operator-(int x) {
        poly a;a.f=f;a.f[0]=(a.f[0]-x<0)?(a.f[0]-x+MOD):(a.f[0]-x); 
        return a;
    }
    inline poly operator*(int a) {
        poly tmp;tmp.f=f;
        for(int i=0;i<f.size();i++) tmp.f[i]=1ll*tmp.f[i]*a%MOD;
        return tmp;
    } 
    inline poly operator/(int a) {
        poly tmp;tmp.f=f;a=ni(a);
        for(int i=0;i<f.size();i++) tmp.f[i]=1ll*tmp.f[i]*a%MOD;
        return tmp;
    } 
    inline poly operator*(poly a) {
        if(a.f.size()<=16||f.size()<=16) {
            poly tp;
            tp.f.resize(f.size()-1+a.f.size());
            for(int i=0;i<f.size();i++) {
                for(int j=0;j<a.f.size();j++) {
                    int as=1ll*f[i]*a.f[j]%MOD;
                    tp.f[i+j]=(tp.f[i+j]+as)>=MOD?(tp.f[i+j]+as)-MOD:(tp.f[i+j]+as);
                }
            }
            return tp;
        }
        int n=std::max(f.size()-1,a.f.size()-1),lim=1,x=-1,ss=f.size()-1+a.f.size();
        while(lim<=(n<<1)) {
            lim<<=1;
            x++;
        }
        for(int i=1;i<=lim;i++) rev[i]=(rev[i>>1]>>1)|((i&1)<<x);
        poly tmp;tmp.f=f;
        tmp.f.resize(lim+1);
        a.f.resize(lim+1);
        NTT(tmp.f,1,lim,g);
        NTT(a.f,1,lim,g);
        for(int i=0;i<=lim;i++) tmp.f[i]=1ll*tmp.f[i]*a.f[i]%MOD;
        NTT(tmp.f,-1,lim,g);
        tmp.f.resize(ss);
        return tmp;     
    } 
    inline poly dao(void) {
        poly tmp;
        for(int i=1;i<f.size();i++) {
            tmp.f.push_back(1ll*f[i]*i%MOD);
        }
        return tmp;
    } 
    inline poly ivdao(void) {
        poly tmp;
        tmp.f.push_back(0);
        for(int i=0;i<f.size();i++) {
            tmp.f.push_back(1ll*f[i]*iv[i+1]%MOD*p[i]%MOD);
        }
        return tmp;
    } 
    inline poly sqr(void) {
        if(f.size()<=16) {
            poly tp;
            tp.f.resize(f.size()-1+f.size());
            for(int i=0;i<f.size();i++) {
                for(int j=0;j<f.size();j++) {
                    int as=1ll*f[i]*f[j]%MOD;
                    tp.f[i+j]=(tp.f[i+j]+as)>=MOD?(tp.f[i+j]+as)-MOD:(tp.f[i+j]+as);
                }
            }
            return tp;
        }
        int n=f.size()-1,lim=1,x=-1,ss=f.size()-1+f.size();
        while(lim<=(n<<1)) {
            lim<<=1;
            x++;
        }
        for(int i=1;i<=lim;i++) rev[i]=(rev[i>>1]>>1)|((i&1)<<x);
        poly tmp;tmp.f=f;
        tmp.f.resize(lim+1);
        NTT(tmp.f,1,lim,g);
        for(int i=0;i<=lim;i++) tmp.f[i]=1ll*tmp.f[i]*tmp.f[i]%MOD;
        NTT(tmp.f,-1,lim,g);
        tmp.f.resize(ss);
        return tmp;     
    } 
    inline poly inv(void) {
        poly tmp,tmp3;tmp3.f.push_back(f[0]);
        tmp.f.push_back(ni(f[0]));
        int s=f.size(),qq=0,a[30];
        a[++qq]=s;
        while(s>1) a[++qq]=(s+1)/2,s=a[qq];
        for(int i=qq-1;i>=1;i--) {
            for(int j=a[i+1];j<a[i];j++) tmp3.f.push_back(f[j]);
            tmp=tmp*2-tmp3*tmp.sqr();
            tmp.f.resize(a[i]);
        }
        return tmp;
    }
    inline poly ln(void) {
        poly qq=(this->dao()*this->inv()).ivdao();
        qq.f.resize(f.size());
        return qq;
    }
    inline poly exp(void) {
        poly tmp,tmp3;tmp3.f.push_back(f[0]);
        tmp.f.push_back(1);
        int s=f.size(),a[30],qq=0;
        a[++qq]=s;
        while(s>1) a[++qq]=(s+1)/2,s=a[qq];
        for(int i=qq-1;i>=1;i--) {
            for(int j=a[i+1];j<a[i];j++) tmp3.f.push_back(f[j]);
            poly tmp4=tmp;
            tmp.f.resize(a[i]);
            tmp=tmp4*(tmp3-tmp.ln()+1);
            tmp.f.resize(a[i]);
        }
        return tmp;
    }
    inline poly sqrt(void) {
        poly tmp,tmp3;tmp3.f.push_back(f[0]);
        tmp.f.push_back(1);
        int s=f.size(),a[30],qq=0;
        a[++qq]=s;
        while(s>1) a[++qq]=(s+1)/2,s=a[qq];
        for(int i=qq-1;i>=1;i--) {
            for(int j=a[i+1];j<a[i];j++) tmp3.f.push_back(f[j]);
            poly tmp5=tmp3+tmp.sqr();
            tmp.f.resize(a[i]);
            tmp=tmp5*(tmp*2).inv();
            tmp.f.resize(a[i]);
        }
        return tmp;     
    }
    inline poly ksm(int x) {
        if(x<64) {
            poly a,b;
            a.f=f;
            b.f.push_back(1); 
            while(x) {
                if(x&1) b=b*a;
                b.f.resize(f.size());
                x>>=1;
                a=a.sqr();
                a.f.resize(f.size());
            }
            return b;
        }
        poly tmp;tmp.f=f;
        tmp=tmp.ln();
        tmp=tmp*x;
        tmp=tmp.exp();
        return tmp;
    }
};
poly q[400009],tpttt;
#define ls (n<<1)
#define rs ((n<<1)|1)
#define md ((l+r)>>1)
poly mulT(poly a,poly b) {
    int n=a.f.size(),m=b.f.size(); 
    std::reverse(b.f.begin(),b.f.end()),b=b*a;
    for(int i = 0;i < n;i++) a.f[i]=b.f[i+m-1];
    return a;
}
void sv(poly &a,int n,int l,int r) {
    if(l==r) {
        q[n]=tpttt;
        q[n].f[0]=1,q[n].f[1]=(MOD-a.f[l])%MOD;
        return;
    }
    sv(a,ls,l,md),sv(a,rs,md+1,r);
    q[n]=q[ls]*q[rs];
}
void qiu(int n,int l,int r,poly f,poly& g) {
    f.f.resize(r-l+1);
    if(l==r) {
        g.f[l]=f.f[0];
        return;
    }
    qiu(ls,l,md,mulT(f,q[rs]),g);
    qiu(rs,md+1,r,mulT(f,q[ls]),g);
}
void multi(poly f,poly a,poly& v,int n) {
    f.f.resize(n+1);
    a.f.resize(n);
    sv(a,1,0,n-1);
    v.f.resize(n);
    qiu(1,0,n-1,mulT(f,q[1].inv()),v);
}
int N,M,l[100009],r[100009],s[100009],s1[100009],s2[100009],tp[100009],tp1[100009],tp2[100009];
struct n_t{
	int x,y;
};
std::vector<n_t> tpt,t1[400009];
void up(int n,int l,int r,int L,int R,int x,int y) {
	if(r<L||R<l) return;
	if(L<=l&&r<=R) {
		t1[n].push_back((n_t){x,y});
		return;
	}
	up(ls,l,md,L,R,x,y);
	up(rs,md+1,r,L,R,x,y);
}
poly svv(int l,int r) {
	if(l==r) {
		poly x;
		x.f.push_back(tpt[l].y);
		x.f.push_back((tpt[l].x+MOD)%MOD);
		return x;
	}
	return svv(l,md)*svv(md+1,r);
}
int xx[1009];
inline bool cmp(n_t x,n_t y) {
	if(x.x==y.x) return x.y<y.y;
	return x.x<y.x;
}
void build(int n,int l,int r) {
	if(l<r) {
		build(ls,l,md),build(rs,md+1,r);
	}
	if(t1[n].empty()) return;
	tpt=t1[n];t1[n].clear();
	std::sort(tpt.begin(),tpt.end(),cmp);
	int ss=0;
	xx[0]=0;
	for(int i=1;i<tpt.size()&&ss<=1000;i++) {
		if(tpt[i].x!=tpt[i-1].x||tpt[i].y!=tpt[i-1].y) xx[++ss]=i;
	}
	xx[ss+1]=tpt.size();
	if(ss<=1000) {
		for(int i=l;i<=r;i++) {
			for(int j=1;j<=ss+1;j++) {
				int id=xx[j]-1;
				tp[i]=1ll*tp[i]*pw((1ll*tpt[id].x*i+tpt[id].y+MOD)%MOD,xx[j]-xx[j-1])%MOD;
			}
		}
		return;
	}
	poly x=svv(0,tpt.size()-1),g,v;
	for(int i=l;i<=r;i++) g.f.push_back(i); 
    multi(x,g,v,std::max(x.f.size(),g.f.size()));	
	for(int i=l;i<=r;i++) tp[i]=1ll*tp[i]*v.f[i-l]%MOD;
}
int sv(int fl) {
	int anss=1,ss2=0,ss1=0,num=0;
	for(int i=1;i<=M;i++) tp[i]=1,s1[i]=s2[i]=1;
	memset(s,0,sizeof(s));
	for(int i=1;i<=N;i++) {
		if(l[i]>=0&&r[i]>=0) {
		} else if(r[i]>=0) {
			anss=1ll*anss*(r[i]+fl)%MOD;
		} else if(l[i]>=0) {
			anss=1ll*anss*(M-l[i]+1+fl)%MOD;
		} else {
			anss=1ll*anss*(1ll*(M+fl)*(M+1+fl)/2%MOD)%MOD;
		}
		if(l[i]>=0&&r[i]>=0) {
			s[l[i]]++;
			s[r[i]+1]--;
		} else if(r[i]>=0) {
			s1[r[i]+1]=1ll*s1[r[i]+1]*(r[i]+fl)%MOD;
		} else if(l[i]>=0) {
			s2[l[i]-1]=1ll*s2[l[i]-1]*(M-l[i]+1+fl)%MOD;
		} else {
			num++;
		}
	} 
	for(int i=1;i<=M;i++) s[i]+=s[i-1];
	for(int i=2;i<=M;i++) s1[i]=1ll*s1[i]*s1[i-1]%MOD;
	for(int i=M-1;i>=1;i--) s2[i]=1ll*s2[i]*s2[i+1]%MOD;
	int su=0;
	for(int i=1;i<=M;i++) {
		int ans=pw(2,s[i]);
		if(fl==0) ans=1ll*ans*tp1[i]%MOD;
		else ans=1ll*ans*tp2[i]%MOD;
		ans=1ll*ans*s1[i]%MOD;
		ans=1ll*ans*s2[i]%MOD;
		ans=1ll*ans*pw((1ll*(M+fl)*(M+1+fl)/2+1ll*i*(M-i+1))%MOD,num)%MOD;
		su=(su+ans)%MOD;
	}	
	su=(su-1ll*M*anss%MOD+MOD)%MOD;
	return su;
} 
signed main(void) {
//	freopen("m.in","r",stdin);
	tpttt.f.resize(2);
	//N=100000;M=100000;
	N=read();M=read();
	int ans=1;
	std::mt19937 rng(114);
	for(int i=1;i<=N;i++) {
	//	l[i]=rng()%250+1;r[i]=-1; 
	//	if(rng()%2) {
	//		l[i]=-1;r[i]=M-rng()%250+1;
	//	}
		//std::swap(l[i],r[i]);
		l[i]=read();r[i]=read();
		if(l[i]>0&&r[i]>0) {
		} else if(r[i]>0) {
			ans=1ll*ans*r[i]%MOD;
			if(r[i]>1) up(1,1,M,1,r[i]-1,1,r[i]);
		} else if(l[i]>0) {
			ans=1ll*ans*(M-l[i]+1)%MOD;
		} else {
			ans=1ll*ans*(1ll*M*(M+1)/2%MOD)%MOD;
		}
	}
	for(int i=1;i<=M;i++) tp[i]=1;
	build(1,1,M);
	for(int i=1;i<=M;i++) {
		tp2[i]=tp1[i]=tp[i];
	}
	for(int i=1;i<=N;i++) {
		if(r[i]>0&&l[i]==-1) tp1[r[i]]=1ll*tp1[r[i]]*(2*r[i])%MOD; 
	}
	for(int i=1;i<=N;i++) {
		if(l[i]>=0&&r[i]>=0) {
		} else if(r[i]>=0) {
		} else if(l[i]>=0) {
			if(l[i]<M) up(1,2,M,l[i]+1,M,-1,2*(M+1)-l[i]);
			tp1[l[i]]=1ll*tp1[l[i]]*(2*(M+1-l[i]))%MOD;
		} else {
		}
	} 	
	for(int i=1;i<=M;i++) tp[i]=1;
	build(1,2,M);
	for(int i=1;i<=M;i++) tp1[i]=1ll*tp1[i]*tp[i]%MOD;
	for(int i=2;i<=M;i++) tp2[i-1]=1ll*tp2[i-1]*tp[i]%MOD;
	int as=sv(0);M--; 
	for(int i=1;i<=N;i++) {
		if(r[i]>0) r[i]--;
	}
	as=(as+MOD-sv(1))%MOD;
	printf("%d",as);
}