#include<bits/stdc++.h>
#define LL long long
#define SZ(x) ((LL)(x.size()))
#define all(x) (x).begin(),(x).end()
using namespace std;
inline LL read(){
  LL q=0,w=1;char ch=getchar();
  while(ch>'9' || ch<'0'){if(ch=='-')w=-1;ch=getchar();}
  while(ch>='0'&&ch<='9'){q=q*10+(ch-'0');ch=getchar();}
  return q*w;
}
void write(LL x){
  if(x<0){putchar('-');x=(-x);}
  if(x>9)write(x/10);
  putchar('0'+x%10);
}
inline void writeln(LL x){write(x);puts("");}
inline void writecs(LL x){write(x);putchar(' ');}

inline void dmin(LL &x,LL y){if(x>y)x=y;return ;}
inline void dmax(LL &x,LL y){if(x<y)x=y;return ;}

#define cout cerr
#define pb push_back

inline LL qpow(LL a,LL b,LL p){LL ans=1;while(b){if(b&1)ans=(ans*a)%p;b>>=1;a=(a*a)%p;}return ans;}
const LL mod = 998244353 ;
inline void amod(LL &x,LL y){x+=y;if(x>=mod)x-=mod;}
inline void smod(LL &x,LL y){x-=y;if(x<0)x+=mod;}
inline LL dmod(LL x){if(x<0)x+=mod;if(x>=mod)x-=mod;return x;}
inline LL inv(LL x){return qpow(x,mod-2,mod);}

template<LL N>struct gauss{
  LL n,a[N][N+1];
  inline void clear(){
    for(LL t=1;t<=n;t++){for(LL i=1;i<=n+1;i++)a[t][i]=0;}
    return ;
  }
  inline void solve(){
    for(LL t=1;t<=n;t++){
      LL T=-1;
      for(LL i=t;i<=n;i++)if(a[i][t]){T=i;break;}
      assert(T!=-1);
      if(t!=T){for(LL i=t;i<=n+1;i++){swap(a[t][i],a[T][i]);}}
      LL u=inv(a[t][t]);for(LL i=t;i<=n+1;i++)a[t][i]=(a[t][i]*u)%mod;
      for(LL j=1;j<=n;j++){
	if(j==t)continue;
	LL k=a[j][t];
	for(LL i=t;i<=n+1;i++)smod(a[j][i],a[t][i]*k%mod);
      }
    }
    return ;
  }
};

const LL N = 100+95 ;
LL n,m,S,T;gauss<N>mat;struct item{LL y,o;};vector<item>E[N];

LL deg[N],p[N],f[N],g[N];

int main(){
  n=read();m=read();S=read();T=read();mat.n=n;
  for(LL t=1;t<=m;t++){LL x=read(),y=read(),o=read();E[x].pb((item){y,o});deg[x]++;}

  mat.clear();
  //p[x]:从点 x 出发到终点仅经过所有 1 边的概率
  for(LL x=1;x<=n;x++){
    if(x==T){mat.a[x][x]=1;mat.a[x][n+1]=1;continue;}
    LL inv_deg_x=inv(deg[x]);
    for(auto u:E[x]){
      LL y=u.y,o=u.o;
      if(o==1)amod(mat.a[x][y],inv_deg_x);
    }
    smod(mat.a[x][x],1);
  }
  mat.solve();
  for(LL x=1;x<=n;x++)p[x]=mat.a[x][n+1];

  mat.clear();
  //f[x]:从点 x 出发到终点仅经过所有 1 边的期望(仅考虑所有 1 边)
  for(LL x=1;x<=n;x++){
    if(x==T){mat.a[x][x]=1;mat.a[x][n+1]=0;continue;}
    LL cnt=0;for(auto u:E[x])cnt+=((u.o==1)?(1):(0));
    LL inv_cnt_x=inv(cnt);
    for(auto u:E[x]){
      LL y=u.y,o=u.o;
      if(o==1)amod(mat.a[x][y],inv_cnt_x);
    }
    smod(mat.a[x][x],1);smod(mat.a[x][n+1],1);
  }
  mat.solve();
  for(LL x=1;x<=n;x++)f[x]=mat.a[x][n+1];

  mat.clear();
  //g[x]:从点 x 出发到终点的期望
  for(LL x=1;x<=n;x++){
    if(x==T){mat.a[x][x]=1;mat.a[x][n+1]=0;continue;}
    LL inv_deg_x=inv(deg[x]);
    for(auto u:E[x]){
      LL y=u.y,o=u.o;
      if(o==1&&y!=T)amod(mat.a[x][y],inv_deg_x);
      if(o==0)amod(mat.a[x][y],inv_deg_x);
    }
    smod(mat.a[x][x],1);smod(mat.a[x][n+1],p[x]*f[x]%mod);
  }
  mat.solve();
  for(LL x=1;x<=n;x++)g[x]=mat.a[x][n+1];

  //  for(LL x=1;x<=n;x++)cout<<" x = "<<x<<" p[x] = "<<p[x]<<" f[x] = "<<f[x]<<" g[x] = "<<g[x]<<endl;

  writecs(f[S]);writeln(0);
  return 0;
}