from collections import deque

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

surv_list = []
for _ in range(int(input())):
    j, k = (int(x) for x in input().split())
    j -= 1
    surv_list.append((k, j))

under_surv = [False] * N
surv_list.sort()
q = deque()
while surv_list:
    under_surv[surv_list[-1][1]] = True
    q.append(surv_list.pop())
    while q:
        k, u = q.popleft()
        while surv_list and surv_list[-1][0] == k:
            if under_surv[surv_list[-1][1]]:
                surv_list.pop()
                continue
            under_surv[surv_list[-1][1]] = True
            q.appendleft(surv_list.pop())
        if k == 0:
            break
        for v in graph[u]:
            if under_surv[v]:
                continue
            under_surv[v] = True
            q.append((k - 1, v))

if under_surv[0]:
    print("No")
    exit()

dist = [-1] * N
dist[0] = 0
q = deque([0])
while q:
    u = q.popleft()
    for v in graph[u]:
        if dist[v] != -1 or under_surv[v]:
            continue
        dist[v] = dist[u] + 1
        q.append(v)

if dist[-1] == -1:
    print("No")
else:
    print("Yes")
    print(dist[-1])