from collections import deque
import heapq
import sys
input = sys.stdin.readline
N, M = map(int, input().split())
G = [[] for _ in range(N)]
for _ in range(M):
    u, v = map(int, input().split())
    u-=1
    v-=1
    G[u].append(v)
    G[v].append(u)
L = int(input())
JK = [list(map(int, input().split())) for _ in range(L)]
hp = []
INF = 10**9
dist = [INF for _ in range(N)]
JK.sort(key=lambda x:x[1])
for j, k in JK:
    j-=1
    if dist[j] > k:
        dist[j] = k
        if k>0:
            hp.append((k, j))
heapq.heapify(hp)
while hp:
    d, v = heapq.heappop(hp)
    for nv in G[v]:
        if dist[nv]>dist[v]-1:
            dist[nv] = dist[v]-1
            if dist[nv]>0:
                heapq.heappush(hp, (dist[nv], nv))
dist2 = [INF for _ in range(N)]
deq = deque()
if dist[0]==INF:
    deq.append(0)
    dist2[0] = 0
while deq:
    v = deq.popleft()
    for nv in G[v]:
        if dist[nv]!=INF:
            continue
        if dist2[nv]>dist2[v]+1:
            dist2[nv] = dist2[v]+1
            deq.append(nv)
if dist2[N-1]==INF:
    print("No")
else:
    print("Yes")
    print(dist2[N-1])