#include <bits/stdc++.h>
#include <iomanip>
#include <numbers>
using namespace std;
using ll = long long;
using ull = unsigned long long;
using l3 = __int128;
using pint = pair<int, int>;
using pll = pair<ll, ll>;
using tint = tuple<int, int, int>;
using tll = tuple<ll, ll, ll>;
template <typename T>
using min_priority_queue = priority_queue<T, vector<T>, greater<T>>;
#define rep(i, n) for (int i = 0; i < (n); ++i)
template <typename T>
bool chmax(T &a, const T &b){if(a<b){a=b;return true;}return false;}
template <typename T>
bool chmin(T &a, const T &b){if(a>b){a=b;return true;}return false;}
const int inf = 1e9;
const ll linf = 1e18;
const int dy[] = {0, 1, 0, -1}, dx[] = {1, 0, -1, 0};

int main(){
  int n,m;cin>>n>>m;
  vector<vector<int>> graph(n);
  rep(i,m){
    int u,v;cin>>u>>v;
    u--,v--;
    graph[u].push_back(v);
    graph[v].push_back(u);
  }
  int l;cin>>l;
  vector<int> dp(n,-1);
  rep(i,l){
    int j,k;cin>>j>>k;
    j--;
    chmax(dp[j],k);
  }
  rep(i,1000)
    rep(v,n)
      for(auto& nv:graph[v])chmax(dp[nv],dp[v]-1);
  queue<int> q;
  vector<int> dist(n,inf);
  q.push(0);
  dist[0]=0;
  while(q.size()){
    int v=q.front();q.pop();
    for(auto& nv:graph[v]){
      if(dp[nv]>=0||dist[nv]<=dist[v]+1)continue;
      dist[nv]=dist[v]+1;
      q.emplace(nv);
    }
  }
  if(dist[n-1]==inf)cout<<"No\n";
  else cout<<"Yes\n"<<dist[n-1]<<endl;
}