#include <bits/stdc++.h>
using namespace std;
int main()
{
    int N, M;
    cin >> N >> M;
    vector<vector<int>> g(N);
    int u, v;
    for (int i = 0; i < M; ++i)
    {
        cin >> u >> v;
        u--, v--;
        g[u].push_back(v);
        g[v].push_back(u);
    }
    int L;
    cin >> L;
    priority_queue<pair<int, int>> que;
    int J, K;
    vector<int> ng(N, -1);
    for (int i = 0; i < L; ++i)
    {
        cin >> J >> K;
        J--;
        que.emplace(K, J);
    }
    while (que.size())
    {
        int a = que.top().first, b = que.top().second;
        que.pop();
        if (ng[b] != -1)
            continue;
        ng[b] = a;
        if (a == 0)
            continue;
        for (auto x : g[b])
        {
            if (ng[a] != -1)
                continue;
            que.emplace(a - 1, x);
        }
    }
    if (ng[0] != -1)
    {
        cout << -1 << endl;
        return 0;
    }
    vector<int> len(N, -1);
    len[0] = 0;
    queue<int> que2;
    que2.push(0);
    while (que2.size())
    {
        int tmp = que2.front();
        que2.pop();
        for (auto x : g[tmp])
        {
            if (len[x] != -1)
                continue;
            if (ng[x] != -1)
                continue;
            que2.push(x);
            len[x] = len[tmp] + 1;
        }
    }
    if (len[N - 1] == -1)
        cout << "No" << endl;
    else
    {
        cout << "Yes" << endl;
        cout << len[N - 1] << endl;
    }
    return 0;
}