#include <iostream>
#include <vector>
#include <algorithm>
#include <cmath>
#include <queue>
#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
using ll = long long;
using mint = modint998244353;
using vi = vector<int>;
using vvi = vector<vi>;
using vvvi = vector<vvi>;
using vll = vector<ll>;
using vvll = vector<vll>;
using vvvll = vector<vvll>;
using vmi = vector<mint>;
using vvmi = vector<vmi>;
using vvvmi = vector<vvmi>;
#define all(a) (a).begin(), (a).end()
#define rep2(i, m, n) for (int i = (m); i < (n); ++i)
#define rep(i, n) rep2(i, 0, n)
#define drep2(i, m, n) for (int i = (m)-1; i >= (n); --i)
#define drep(i, n) drep2(i, n, 0)
using p = pair<int, int>;
void solve(){
    
}

int main(){
    int n, m; cin >> n >> m;
    vvi adj(n);
    rep(i, m){
        int u, v; cin >> u >> v;
        adj[u-1].push_back(v-1);
        adj[v-1].push_back(u-1);
    }
    int l; cin >> l;
    vi dist(n, -1);
    priority_queue<p> pq;
    rep(i, l){
        int j, k; cin >> j >> k;
        dist[j-1] = k;
        if(k > 0)pq.push({k, j-1});
    }
    while(!pq.empty()){
        auto [d, u] = pq.top(); pq.pop();
        if(d < dist[u])continue;
        for(auto v : adj[u]){
            if(dist[v] == -1 || dist[v] < dist[u]-1){
                dist[v] = dist[u]-1;
                if(dist[v] > 0)pq.push({dist[v], v});
            }
        }
    }
    if(dist[0] >= 0 || dist[n-1] >= 0){
        cout << "No" << endl;
        return 0;
    }
    queue<int> q; q.push(0);
    vi d2(n, -1); d2[0] = 0;
    while(!q.empty()){
        auto u = q.front(); q.pop();
        for(auto v : adj[u]){
            if(dist[v] >= 0)continue;
            if(d2[v] == -1){
                d2[v] = d2[u] + 1;
                q.push(v);
                if(v == n-1){
                    cout << "Yes" << endl;
                    cout << d2[n-1] << endl;
                    return 0;
                }
            }
        }
    }
    cout << "No" << endl;
    return 0;
}