from heapq import heappop, heappush
from collections import deque

INF = 10**18

N, M = map(int, input().split())

graph = [[] for _ in range(N)]
for _ in range(M):
    u, v = map(int, input().split())
    u -= 1
    v -= 1
    graph[u].append(v)
    graph[v].append(u)

L = int(input())

forbidden = [0] * N
pq = []

for _ in range(L):
    j, k = map(int, input().split())
    j -= 1
    
    forbidden[j] = max(forbidden[j], k)
    heappush(pq, (-(k + 1), j))

while pq:
    k, j = heappop(pq)
    k = -k
    for i in graph[j]:
        if forbidden[i] < k - 1:
            heappush(pq, (-(k - 1), i))
            forbidden[i] = k - 1

if forbidden[0] > 0 or forbidden[N - 1] > 0:
    print("No")
    exit()

que = deque([0])
dist = [INF] * N
dist[0] = 0

while que:
    v = que.popleft()
    for nv in graph[v]:
        if forbidden[nv] == 0 and dist[nv] >= INF:
            dist[nv] = dist[v] + 1
            que.append(nv)

if dist[N - 1] < INF:
    print("Yes")
    print(dist[N - 1])
else:
    print("No")