#include <iostream>
#include <ranges>
#include <algorithm>
#include <vector>
using namespace std;
using ll=long long;

#include <atcoder/all>
using mint=atcoder::modint998244353;

ostream& operator<<(ostream& os,mint& x){
	os<<x.val();
	return os;
}
istream& operator>>(istream& is,mint& x){
	int t;
	is>>t;
	x=t;
	return is;
}

template <typename S,typename T>
ostream& operator<<(ostream& os,const pair<S,T>& p);
template <typename S,typename T>
istream& operator>>(istream& is,pair<S,T>& p);
template <typename T,size_t n>
ostream& operator<<(ostream& os,const array<T,n>& arr);
template <typename T,size_t n>
istream& operator>>(istream& is,array<T,n>& arr);
template <typename T>
ostream& operator<<(ostream& os,const vector<T>& vec);
template <typename T>
istream& operator>>(istream& is,vector<T>& vec);

template <typename S,typename T>
ostream& operator<<(ostream& os,pair<S,T>& p){
	os<<p.first<<" "<<p.second;
	return os;
}
template <typename S,typename T>
istream& operator>>(istream& is,pair<S,T>& p){
	is>>p.first>>p.second;
	return is;
}

template <typename T,size_t n>
ostream& operator<<(ostream& os,array<T,n>& arr){
	for(int i=0;i<n;i++)os<<arr[i]<<(i+1==n?"":" ");
	return os;
}
template <typename T,size_t n>
istream& operator>>(istream& is,array<T,n>& arr){
	for(int i=0;i<n;i++)is>>arr[i];
	return is;
}
template <typename T>
ostream& operator<<(ostream& os,vector<T>& vec){
	for(int i=0;i<vec.size();i++)os<<vec[i]<<(i+1==vec.size()?"":" ");
	return os;
}
template <typename T>
istream& operator>>(istream& is,vector<T>& vec){
	for(int i=0;i<vec.size();i++)is>>vec[i];
	return is;
}

template <typename T>
vector<T> make_unique(vector<T> vec){
	ranges::sort(vec);
	vec.erase(unique(vec.begin(),vec.end()),vec.end());
	return vec;
}

template <typename T>
vector<int> make_rank(vector<T> vec){
	int n=vec.size();
	vector<int> res(n);
	iota(res.begin(),res.end(),0);
	ranges::sort(vec,{},[&](int i)->T{
		return vec[i];
	});
	return res;
}


int main(){
	cin.tie(nullptr);
	ios::sync_with_stdio(false);
	int n;
	cin>>n;
	int m;
	cin>>m;
	vector<vector<mint>> mat(n,vector<mint>(n));
	vector<vector<int>> graph(n);
	for(int i=0;i<m;i++){
		int u,v;
		cin>>u>>v;
		u--;v--;
		graph[u].push_back(v);
		graph[v].push_back(u);
	}
	for(int i=0;i<n;i++){
		if(graph[i].empty())continue;
		mint s=graph[i].size();
		s=s.inv();
		for(int j:graph[i])mat[i][j]=s;
		//cout<<mat[i]<<endl;
	}
	ll s,t,a,b;
	cin>>s>>t>>a>>b;
	a--;b--;s--;t--;
	auto f=[&](ll x,ll y,ll l)->mint{
		auto matt=mat;
		vector<vector<mint>> e(n,vector<mint>(n));
		for(int i=0;i<n;i++)e[i][i]=1;
		ll l2=l;
		while(l>0){
			if(l&1){
				vector<vector<mint>> ne(n,vector<mint>(n));
				for(int i=0;i<n;i++)for(int j=0;j<n;j++)for(int k=0;k<n;k++)ne[i][j]+=e[i][k]*matt[k][j];
				e=ne;
			}
			vector<vector<mint>> nmat(n,vector<mint>(n));
			for(int i=0;i<n;i++)for(int j=0;j<n;j++)for(int k=0;k<n;k++)nmat[i][j]+=matt[i][k]*matt[k][j];
			matt=nmat;
			l>>=1;
		}
		//cout<<x<<" "<<y<<" "<<l2<<" "<<e[x][y]<<endl;
		return e[x][y];
	};
	cout<<((f(0,b,t)*f(b,a,s-t))/f(0,a,s)).val()<<endl;
}