#include<bits/stdc++.h>
using namespace std;
using ll=long long;



int main(){
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    
    ll N,M;
    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);
    }
    vector<ll> D(N,-1e18);
    ll L;
    cin>>L;
    for(int i=0;i<L;i++){
        ll J,K;
        cin>>J>>K;
        D[J-1]=max(D[J-1],K);
    }
    priority_queue<array<ll,2>> Q;
    for(int i=0;i<N;i++){
        if(D[i]>=0)Q.push({D[i],i});
    }
    vector<bool> seen(N,0);
    while(!Q.empty()){
        auto [d,p]=Q.top();
        Q.pop();
        if(seen[p])continue;
        seen[p]=1;
        if(d==0)continue;
        for(int v:G[p]){
            if(D[v]>=D[p]-1)continue;
            if(seen[v])continue;
            D[v]=D[p]-1;
            Q.push({D[v],v});
        }
    }
    if(seen[0]||seen[N-1]){
        cout<<"No\n";
        return 0;
    }
    vector<ll> dist(N,1e18);
    dist[0]=0;
    queue<int> que;
    que.push(0);
    while(!que.empty()){
        int p=que.front();
        que.pop();
        if(seen[p])continue;
        seen[p]=1;
        for(int v:G[p]){
            if(seen[v])continue;
            if(dist[v]<=dist[p]+1)continue;
            dist[v]=dist[p]+1;
            que.push(v);
        }
    }
    if(dist[N-1]<1e17){
        cout<<"Yes\n";
        cout<<dist[N-1]<<endl;
    }
    else cout<<"No\n";
    
}