#include<cstdio>
#include<cctype>

#define maxn 505505

const int mod=998244353;

template<class T>

inline T read(){
    T r=0,f=0;
    char c;
    while(!isdigit(c=getchar()))f|=(c=='-');
    while(isdigit(c))r=(r<<1)+(r<<3)+(c^48),c=getchar();
    return f?-r:r;
}

template<class T>

inline T min(T a,T b){
	return a<b?a:b;
}

int n,w,B,lim;

int tmp[2222][2222],*f[maxn],g[2][maxn];

inline void Add(int &x,int y){
	x+=y-mod,x+=(x>>31)&mod;
}

int main(){
    n=read<int>();
    w=read<int>()%mod;
    while(B*(B+1)/2<n)B++;
    for(lim=B+1;lim*(lim+1)/2-B*(B+1)/2<=n;lim++);
    for(int i=0;i<=n;i++)f[i]=tmp[i%lim];
    for(int i=1;i<=B;i++)f[i][i]=1;
    for(int i=1;i<n;i++){
    	int Lim=min(min(i,lim),n-i+1);
    	for(int j=1;j<=Lim;j++){
    		if(!f[i][j])continue;
    		if(j>1)f[i+j-1][j-1]=(f[i+j-1][j-1]+1ll*f[i][j]*w)%mod;
    		if(i+j+1<=n)Add(f[i+j+1][j+1],f[i][j]);
    		f[i][j]=0;
    	}
    }
    int LIM=2*n/(B+1)-1,L=(LIM+1)*(B+1);
    for(int i=LIM,o=LIM&1;~i;i--,o^=1){
    	int Lim=2*n/(i+1);
    	for(int j=B+1;j<=Lim;j++)
			g[o][j*(i+1)]++;
    	if(!i)break;
    	L=min(L,(B+1)*(i+1));
    	for(int j=L;j<=2*n;j++){
    		if(!g[o][j])continue;
    		if(j+i<=2*n)Add(g[o^1][j+i],g[o][j]);
    		g[o^1][j-i]=(g[o^1][j-i]+1ll*g[o][j]*w)%mod;
    		g[o][j]=0;
    	}
    	L-=i;
    }
    long long ans=g[0][n];
    for(int i=1;i<=lim;i++)ans+=f[n][i];
    printf("%lld\n",ans%mod);
    return 0;
}