#include <bits/stdc++.h>
using namespace std;
#if __has_include("all.hpp")
#include "all.hpp"
#else
#include <atcoder/all>
#endif
using namespace atcoder;
int main(void){
    int n,m,s,g;
    cin>>n>>m>>s>>g;
    s--,g--;
    dsu d(n);
    vector<array<int,2>>v(m);
    for(int i=0;i<n;i++){
        cin>>v[i][0]>>v[i][1];
        v[i][0]--,v[i][1]--;
    }
    int u;
    cin>>u;
    set<int>se;
    while(u--){
        int a;
        cin>>a;
        se.insert(a-1);
    }
    for(int i=0;i<m;i++){
        if(!((se.count(v[i][0]))&&(se.count(v[i][1])))){
            d.merge(v[i][0],v[i][1]);
        }
    }
    cout<<(d.same(s,g)?"Yes":"No")<<endl;
    return 0;
}