#include <iostream>
#include <vector>
#include <queue>
using namespace std;
using Graph = vector<vector<int>>;

int N, M;

Graph G(200010);
bool ok[200010];
int D[200010];



int main(){
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cin>>N>>M;
    for (int i=0;i<M;i++){
        int U, V; cin>>U>>V;
        G[U].push_back(V);
        G[V].push_back(U);
    }
    int L; cin>>L;
    vector<int> rem(N + 1, -1);
    vector<vector<int>> q(1005);


    for (int i = 0; i < L; i++) {
        int J, K; cin >> J >> K;
        rem[J] = max(rem[J], K);
    }

    for (int i = 1; i <= N; i++) {
        if (rem[i] != -1) {
            q[rem[i]].push_back(i);
        }
    }

    for (int k = 1000; k > 0; k--) {
        for (int cur : q[k]) {
            if (rem[cur] > k) continue; 
            
            for (int dst : G[cur]) {
                if (rem[dst] < k - 1) {
                    rem[dst] = k - 1;
                    q[k - 1].push_back(dst);
                }
            }
        }
    }

    for(int i = 1; i <= N; i++){
        ok[i] = (rem[i] == -1);
    }

    if(! ok[1]) {
        cout << "No" << "\n";
        return 0;
    }

    for (int i=1;i<=N;i++) D[i]=-1;
    D[1]=0;
    queue<int> Q;
    Q.push(1);

    while(! Q.empty()){
        int cur = Q.front(); Q.pop();
        for (auto dst:G[cur]){
            if(! ok[dst]) continue;
            if(D[dst]!=-1) continue;
            D[dst]=D[cur]+1;
            Q.push(dst);
        }
    }

    if(D[N]!=-1) {
        cout << "Yes" << "\n";
        cout << D[N] << "\n";
    }
    else cout << "No" << "\n";

    return 0;
}