#include<bits/stdc++.h>
#include<atcoder/modint>
using namespace std;

template<typename T,int N>
struct Matrix{
  array<array<T,N>,N> val;
  Matrix(){
    for (int i=0;i<N;i++) for (int j=0;j<N;j++) val[i][j]=T(0);
  }

  array<T,N> &operator[](int i){return val[i];}
	const array<T,N> &operator[](int i)const{return val[i];}
  Matrix operator*(const Matrix &b){
    Matrix a=*this,c;
    for (int i=0;i<N;i++){
      for (int j=0;j<N;j++){
        for (int k=0;k<N;k++){
          c[i][j]+=a[i][k]*b[k][j];
        }
      }
    }
    return c;
  }

  Matrix e(){
    Matrix ret;
    for (int i=0;i<N;i++) ret.val[i][i]=1;
    return ret;
  }

  Matrix pow(long long k){
    Matrix ret=e(),m=*this;
    while (k>0){
      if (k%2==1) ret=ret*m;
      m=m*m;
      k/=2;
    }
    return ret;
  }
};

int main(){
  using ll=long long;
  using mint=atcoder::modint998244353;
  using mat=Matrix<mint,52>;
  int n,m;
  cin>>n>>m;
  vector<int> d(n);
  vector<vector<int>> g(n);
  for (int i=0;i<m;i++){
    int u,v;
    cin>>u>>v;
    u--;v--;
    d[u]++;
    d[v]++;
    g[u].push_back(v);
    g[v].push_back(u);
  }
  mat one;
  for (int v=0;v<n;v++){
    for (int u:g[v]){
      one[v][u]=mint(d[v]).inv();
    }
  }
  auto f=[&](int u,int v,ll k){
    mat pw=one,ret=one.e();
    while (k){
      if (k&1) ret=ret*pw;
      pw=pw*pw;
      k/=2;
    }
    return ret[u][v];
  };
  ll s,t,a,b;
  cin>>s>>t>>a>>b;
  a--;b--;
  mint ans=(f(0,b,t-1)*f(b,a,s-t))/f(0,a,s-1);
  cout<<ans.val()<<endl;
}