#include <iostream>
#include <vector>
#include <string>
#include <cmath>
#include <cstdlib>
#include <algorithm>
#include <map>
#include <numeric>
using namespace std;
#define ll long long


int main(void)
{
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    ll N, M, L;

    cin >> N >> M;

    map<ll, vector<ll>> d;

    for (ll i = 0; i < M; i++) {
        ll u, v;
        cin >> u >> v;

        if (!d.count(u)) {
            d[u] = {};
        }

        d[u].push_back(v);

        if (!d.count(v)) {
            d[v] = {};
        }
        d[v].push_back(u);
    }

    cin >> L;

    vector<vector<ll>> mem;

    for (ll i = 0; i < L; i++) {
        ll J, K;
        cin >> J >> K;
        mem.push_back({ J, K });
        if (J == 1) {
            cout << "No" << endl;
            return 0;
        }
    }

    sort(mem.begin(), mem.end(), [](const vector<ll>& a, const vector<ll>& b) {
        return a[1] > b[1];
        });

    vector<ll> visited(N, -1);

    for (ll n = 0; n < L; n++) {
        ll a = mem[n][0], b = mem[n][1];
        if (visited[a - 1] < b)
        {
            visited[a - 1] = b;
            if (b == 0) {
                continue;
            }
        }

        vector<ll> stack;
        stack.push_back(a);
        vector<ll> next_move;

        while (!stack.empty()) {
            for (auto i : stack) {
                for (auto j : d[i]) {
                    if (visited[j - 1] == -1 || visited[j - 1] < visited[i - 1] - 1) {
                        visited[j - 1] = visited[i - 1] - 1;
                        if (visited[j - 1] >= 1) {
                            next_move.push_back(j);
                        }
                    }
                }

            }
            stack = next_move;
            next_move.clear();

        }
    }

    vector<ll> res(N, -1);
    res[0] = 0;
    ll ans = 1;
    vector<ll> stack;
    stack.push_back(1);
    vector<ll> next_move;
    while (!stack.empty()) {
        for (auto i : stack) {
            for (auto j : d[i]) {
                if (visited[j - 1] == -1 && res[j - 1] == -1) {
                    res[j - 1] = ans;
                    next_move.push_back(j);
                }
            }

        }
        stack = next_move;
        next_move.clear();
        ans += 1;

    }

    if (res[N - 1] != -1) {
        cout << "Yes" << endl;
        cout << res[N - 1] << endl;
    }
    else {
        cout << "No" << endl;
    }

    return 0;
}