#ifdef ONLINE_JUDGE
#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")
#endif

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

#if __has_include(<atcoder/all>)
#include <atcoder/all>
#endif

constexpr int inf = (1 << 30) - 1;
constexpr long long linf = (1LL << 60) - 1;
using ll = long long;
using ld = long double;
#define len(x) int((x).size())
#define all(x) begin(x), end(x)
#define rall(x) rbegin(x), rend(x)
#define LB(c, x) distance(begin(c), lower_bound(all(c), x))
#define UB(c, x) distance(begin(c), upper_bound(all(c), x))
template <typename F> ll binary_search(F check, ll ok, ll ng, bool CHECK = true) { if(CHECK) assert(check(ok)); while(abs(ok - ng) > 1) { ll mi = (ok + ng) / 2; (check(mi) ? ok : ng) = mi; } return ok; }
template <typename T, typename S> auto min(const T& a, const S& b) { return(a < b ? a : b); }
template <typename T, typename S> auto max(const T& a, const S& b) { return(a > b ? a : b); }
template <typename T, typename S> inline bool chmin(T& a, const S& b) { return(a > b ? a = b, 1 : 0); }
template <typename T, typename S> inline bool chmax(T& a, const S& b) { return(a < b ? a = b, 1 : 0); }

#include <atcoder/dsu>
void solve() {
    int n, m; cin >> n >> m;
    vector<vector<int>> g(n);
    vector<pair<int,int>>E;
    for(int i = 0; i < m; i++) {
        int a, b; cin >> a >> b;
        a--; b--;
        g[a].push_back(b);
        g[b].push_back(a);
        E.push_back({a,b});
    }
    int L;
    cin >> L;
    vector<ll> dp(n, -1);
    for(int i = 0; i < L; i++) {
        int p, h; cin >> p >> h;
        dp[--p] = h;
    }
    priority_queue<pair<ll, ll>> pq;
    for(int i = 0; i < n; i++) if(dp[i] > 0) pq.push({dp[i], i});
    while(!pq.empty()) {
        auto[d, v] = pq.top(); pq.pop();
        if(dp[v] != d) continue;
        if(dp[v] == 0) continue;
        for(auto&&nv: g[v]) {
            if(chmax(dp[nv], dp[v] - 1)) {
                pq.push({dp[nv], nv});
            }
        }
    }
    if(dp[0]>=0) {
        cout << "No" << "\n";
    } else {
        queue<int>Q;
        Q.push(0);
        vector<int>dist(n,-1);
        dist[0]=0;
        while(!Q.empty()) {
            int v = Q.front();
            Q.pop();
            for(int u: g[v]) if(dp[u] < 0 && dist[u]<0) {
                dist[u] = dist[v]+1;
                Q.push(u);
            }
        }
        if(dist.back()<0) cout << "No\n";
        else {
            cout << "Yes\n";
            cout << dist.back() << "\n";
        }
    }
}
int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    int T = 1;
    while(T--) {
        solve();
    }
}