#include<iostream>
#include<vector>
#include<set>
#include<queue>
using namespace std;

int main() {
    int n, m, s, g;
    cin >> n >> m >> s >> g;
    s--; g--;
    vector<vector<int>> gr(n);
    for (int i = 0; i < m; i++) {
        int f, t;
        cin >> f >> t;
        f--; t--;
        gr[f].push_back(t);
        gr[t].push_back(f);
    }
    int u;
    cin >> u;
    set<int> I;
    for (int i = 0; i < u; i++) {
        int j;
        cin >> j;
        j--;
        I.insert(j);
    }
    vector<bool> island(n, false);
    island[s] = true;
    queue<int> check;
    check.push(s);
    while(!check.empty()) {
        int c = check.front();
        for (int i = 0; i < gr[c].size(); i++) {
            if (island[gr[c][i]] == false && !I.count(gr[c][i])) {
                island[gr[c][i]] = true;
                check.push(gr[c][i]);
            }
        }
        check.pop();
    }
    if (island[g]) cout << "Yes" << endl;
    else cout << "No" << endl;
    return 0;
}