#include <bits/stdc++.h>
#include <atcoder/all>

using namespace std;
using namespace atcoder;
typedef long long ll;
typedef modint998244353 mint;
//typedef modint1000000007 mint;

void chmin(ll& a, ll b) { a = min(a, b); }
void chmax(ll& a, ll b) { a = max(a, b); }

int N, M;
bool IsSeen[200200];
int dfs(vector<vector<int>>& G, vector<int> State, int now){
    if(now == N - 1){
        return 0;
    }
    IsSeen[now] = true;
    int ans = INT_MAX / 2;
    for(int i = 0; i < G[now].size(); i++){
        int neighbor = G[now][i];
        if(State[neighbor] == -1 && !IsSeen[neighbor]){
            ans = min(ans, dfs(G, State, neighbor) + 1);
        }
    }
    return ans;
}

int main() {
    cin >> N >> M;
    vector<vector<int>> G(N);
    for(int i = 0; i < M; i++){
        int u, v;
        cin >> u >> v;
        u--; v--;
        G[u].push_back(v);
        G[v].push_back(u);
    }

    int L;
    cin >> L;
    queue<pair<int, int>> Q;
    vector<int> State(N, -1);
    for(int i = 0; i < L; i++){
        int J, K;
        cin >> J >> K;
        J--;
        if(State[J] < K){
            State[J] = K;
            Q.push({J, K});
        }
    }

    // マルチソースBFS
    while(!Q.empty()){
        pair<int, int> now = Q.front();
        Q.pop();
        if(State[now.first] > 0 && State[now.first] == now.second){
            for(int i = 0; i < G[now.first].size(); i++){
                int neighbor = G[now.first][i];
                if(State[neighbor] < State[now.first] - 1){
                    State[neighbor] = State[now.first] - 1;
                    Q.push({neighbor, State[neighbor]});
                }
            }
        }
    }
    
    fill(IsSeen, IsSeen + N, false);
    int result = dfs(G, State, 0);
    if(result > INT_MAX / 3){
        cout << "No" << endl;
    }else{
        cout << "Yes" << endl;
        cout << result << endl;
    }
}