#include <bits/stdc++.h>
using namespace std;
using ll=long long;
const ll ILL=2167167167167167167;
const int INF=2100000000;
#define rep(i,a,b) for (int i=(int)(a);i<(int)(b);i++)
#define all(p) p.begin(),p.end()
template<class T> using pq_ = priority_queue<T, vector<T>, greater<T>>;
template<class T> int LB(vector<T> &v,T a){return lower_bound(v.begin(),v.end(),a)-v.begin();}
template<class T> int UB(vector<T> &v,T a){return upper_bound(v.begin(),v.end(),a)-v.begin();}
template<class T> bool chmin(T &a,T b){if(b<a){a=b;return 1;}else return 0;}
template<class T> bool chmax(T &a,T b){if(a<b){a=b;return 1;}else return 0;}
template<class T> void So(vector<T> &v) {sort(v.begin(),v.end());}
template<class T> void Sore(vector<T> &v) {sort(v.begin(),v.end(),[](T x,T y){return x>y;});}
bool yneos(bool a,bool upp=false){if(a){cout<<(upp?"YES\n":"Yes\n");}else{cout<<(upp?"NO\n":"No\n");}return a;}
template<class T> void vec_out(vector<T> &p,int ty=0){
    if(ty==2){cout<<'{';for(int i=0;i<(int)p.size();i++){if(i){cout<<",";}cout<<'"'<<p[i]<<'"';}cout<<"}\n";}
    else{if(ty==1){cout<<p.size()<<"\n";}for(int i=0;i<(int)(p.size());i++){if(i) cout<<" ";cout<<p[i];}cout<<"\n";}}
template<class T> T vec_min(vector<T> &a){assert(!a.empty());T ans=a[0];for(auto &x:a) chmin(ans,x);return ans;}
template<class T> T vec_max(vector<T> &a){assert(!a.empty());T ans=a[0];for(auto &x:a) chmax(ans,x);return ans;}
template<class T> T vec_sum(vector<T> &a){T ans=T(0);for(auto &x:a) ans+=x;return ans;}
int pop_count(long long a){int res=0;while(a){res+=(int)(a&1),a>>=1;}return res;}
template<class T> T square(T a){return a * a;}

#include <atcoder/modint>
using mint = atcoder::modint998244353;
const int L = 51;
using F = array<array<mint, L>, L>;
F mul(F l, F r) {
    F res;
    rep(i, 0, L) rep(j, 0, L) res[i][j] = 0;
    rep(i, 0, L) rep(j, 0, L) rep(k, 0, L) res[i][k] += l[i][j] * r[j][k];
    return res;
}
F mp(F l, ll t) {
    F res;
    rep(i, 0, L) rep(j, 0, L) res[i][j] = (i == j ? 1 : 0);
    while (t) {
        if (t & 1) res = mul(res, l);
        l = mul(l, l);
        t /= 2;
    }
    return res;
}

void solve();
// DEAR MYSTERIES / TOMOO
int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    int t = 1;
    // cin >> t;
    rep(i, 0, t) solve();
}

void solve(){
    int N, M;
    cin >> N >> M;
    vector<vector<int>> G(N);
    rep(i, 0, M) {
        int a, b;
        cin >> a >> b;
        a--, b--;
        G[a].push_back(b);
        G[b].push_back(a);
    }
    ll S, T, A, B;
    cin >> S >> T >> A >> B, A--, B--;
    F tmp;
    rep(i, 0, L) rep(j, 0, L) tmp[i][j] = 0;
    rep(i, 0, N) {
        mint inv = (mint(G[i].size())).inv();
        for (auto x : G[i]) tmp[i][x] = inv;
    }
    auto tmp1 = mp(tmp, T - 1);
    auto tmp2 = mp(tmp, S - T);
    mint sum = 0, ans = tmp1[0][B] * tmp2[B][A];
    rep(i, 0, N) sum += tmp1[0][i] * tmp2[i][A];
    ans /= sum;
    cout << ans.val() << "\n";
}