#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
istream &operator>>(istream &is, modint &a) { long long v; is >> v; a = v; return is; }
ostream &operator<<(ostream &os, const modint &a) { return os << a.val(); }
istream &operator>>(istream &is, modint998244353 &a) { long long v; is >> v; a = v; return is; }
ostream &operator<<(ostream &os, const modint998244353 &a) { return os << a.val(); }
istream &operator>>(istream &is, modint1000000007 &a) { long long v; is >> v; a = v; return is; }
ostream &operator<<(ostream &os, const modint1000000007 &a) { return os << a.val(); } 

typedef long long ll;
typedef vector<vector<int>> Graph;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
#define FOR(i,l,r) for (int i = l;i < (int)(r); i++)
#define rep(i,n) for (int i = 0;i < (int)(n); i++)
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define my_sort(x) sort(x.begin(), x.end())
#define my_max(x) *max_element(all(x))
#define my_min(x) *min_element(all(x))
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }
const int INF = (1<<30) - 1;
const ll LINF = (1LL<<62) - 1;
const int MOD = 998244353;
const int MOD2 = 1e9+7;
const double PI = acos(-1);
vector<int> di = {1,0,-1,0};
vector<int> dj = {0,1,0,-1};

#ifdef LOCAL
#  include <debug_print.hpp>
#  define debug(...) debug_print::multi_print(#__VA_ARGS__, __VA_ARGS__)
#else
#  define debug(...) (static_cast<void>(0))
#endif

int main(){
    cin.tie(0);
    ios_base::sync_with_stdio(false);

    int N, M;
    cin >> N >> M;

    Graph g(N);
    rep(i, M) {
        int u, v;
        cin >> u >> v;
        u--, v--;
        g[u].push_back(v);
        g[v].push_back(u);
    }

    priority_queue<pii> pq;
    int L; 
    cin >> L;
    vector<int> J(L), K(L);
    vector<int> dp(N, -INF);
    rep(i, L) {
        cin >> J[i] >> K[i];
        J[i]--;

        pq.push({K[i], J[i]});
        chmax(dp[J[i]], K[i]);
    }

    while(!pq.empty()){
        auto [k, j] = pq.top();
        pq.pop();

        if(k == 0) continue;

        for(auto nxt : g[j]) {
            if(dp[nxt] < k - 1) {
                dp[nxt] = k - 1;
                pq.push({dp[nxt], nxt});
            }
        }
    }

    if(dp[0] >= 0){
        cout << "No" << endl;
        return 0;
    }

    vector<int> dist(N, INF);
    dist[0] = 0;
    queue<int> Q;
    Q.push(0);

    while(!Q.empty()){
        auto now = Q.front();
        Q.pop();

        for(int nxt : g[now]){
            if(dist[nxt] != INF) continue;
            if(dp[nxt] >= 0) continue;

            dist[nxt] = dist[now] + 1;
            Q.push(nxt);
        }
    }

    if(dist[N - 1] < INF){
        cout << "Yes" << endl;
        cout << dist[N - 1] << endl;
    }
    else{
        cout << "No" << endl;
    }
}