#pragma GCC optimize("Ofast")
#include<bits/stdc++.h>
#ifdef ONLINE_JUDGE
	#define getchar()(p1==p2&&(p2=(p1=buf)+fread(buf,1,1<<21,stdin),p1==p2)?EOF:*p1++)
	char buf[1<<21],*p1=buf,*p2=buf;
#endif
#define int long long
using namespace std;typedef __int128 lll;int read(){int num=0,f=1;char c;while(!isdigit(c=getchar()))if(c=='-')f=-1;while(isdigit(c))num=num*10+(c&15),c=getchar();return num*f;}void write(int x,char ch=' '){int F[20],cnt=0;if(!x)putchar('0');if(x<0)putchar('-'),x=-x;while(x)F[cnt++]=x%10+'0',x/=10;while(cnt)putchar(F[--cnt]);putchar(ch);}
namespace Main
{
    /*
    F(i)=(i>B?sqrt(k/i):k/(i*i))
    min<=B
    F(a,b)=F(a,a)+F([1,a],[a+1,b])=\sum_{i=a+1}^b min(a,sqrt(k/i)) r=k/(v*v)-1 sqrt(k/j)<min(a,sqrt(k/i))
    sqrt(k/j)<v k/j<v*v j>k/(v*v)
    F(a,a):2*G(a,b) a<=b -min(a,B)
    \sum_{i=1}^a min(k/(i*i),a)-i+1
    v=k/(i*i) k/(j*j)<v j>sqrt(k/v)
    */
    const int N=1000010,mod=998244353,inf=1e18;void Add(int&x,int y){(x+=y)>=mod&&(x-=mod);}int n,m,k,ans,a[N],x,y,z,xx,yy,zz;int sq(int x){return (int)sqrt(1.*x);}int F(int i){return i?(k?(i>m?sq(k/i):k/(i*i)):0):inf;}int S(int x){return (lll)x*(x+1)/2%mod;}
    int G(int x,int y){int res=0;for(int i=x+1,j,z;i<=y;i=j+1)z=min(x,sq(k/i)),j=min(y,k/(z*z)),res=(res+(lll)(j-i+1)*z)%mod;/*printf("G %lld %lld %lld\n",x,y,res);*/return res;}
    int F(int x,int y){if(x>y)swap(x,y);int res=0,r=min(x,m);/*for(int i=1;i<=r;++i)res=(res+min(x,k/(i*i))-i+1)%mod;*/for(int i=1,j,z;i<=r;i=j+1)z=min(x,k/(i*i)),j=min(r,sq(k/z)),/*assert(j>=i),*/res=(res+(lll)(j-i+1)*z)%mod;res=(res+r-S(r)+mod)%mod,res=(res*2+G(x,y)-r+x+y+1+mod)%mod;
    /*int s=0;for(int i=0;i<=x;++i)for(int j=0;j<=y;++j)s+=(min(i,j)*i*j<=k);printf("F %lld %lld %lld %lld\n",x,y,res,s);assert(res==s);*/return res;}
    void main()
    {
        n=read(),k=read(),ans=1;for(int i=1;i<=n;++i)a[i]=read();/*if((n==1&&a[1]==-1)||(a[1]==-1&&a[2]==-1)||(a[n-1]==-1&&a[n]==-1))return write(-1,'\n');for(int i=1;i<=n-2;++i)if(a[i]==-1&&a[i+1]==-1&&a[i+2]==-1)return write(-1,'\n');*/for(int i=1;i<n;++i)if(a[i]>0&&a[i+1]>0&&min(a[i],a[i+1])>k/a[i]/a[i+1])return write(0,'\n');
        for(int i=1,j;i<=n;)if(a[i]!=-1)++i;else{for(j=i;j<n&&a[j+1]==-1;++j);if((j-i+1)+(!a[i-1])+(!a[j+1])>=3)return write(-1,'\n');i=j+1;}if(!k)return write(1,'\n');m=(k?(int)cbrt(1.*k):0);for(;(m+1)*(m+1)*(m+1)<=k;++m);for(;m*m*m>k;--m);
        for(int i=1,j;i<=n;)if(a[i]!=-1)++i;else{for(j=i;j<n&&a[j+1]==-1;++j);if(i==j)ans=(lll)ans*(F(max(a[i-1],a[i+1]))+1)%mod;else ans=(lll)ans*F(F(a[i-1]),F(a[j+1]))%mod;i=j+1;}write(ans,'\n');
        // for(int i=1;i<=100;++i)for(int j=1;j<=100;++j)F(i,j);
    }
}
signed main()
{
    // freopen("ex_seq.in","r",stdin);
    // freopen("ex_seq1.in","r",stdin),freopen(".out","w",stdout);
    const bool base=0,IO=1;int T;if(!base)T=1;else if(IO)T=read();else ios::sync_with_stdio(0),cin>>T;for(;T--;)Main::main();
    return 0;
}