from collections import deque
N,M = list(map(int,input().split()))
edge = [[] for _ in range(N)]
for _ in range(M):
    u,v = list(map(int,input().split()))
    u -= 1;v -= 1
    edge[u].append(v)
    edge[v].append(u)

L = int(input())
q = deque()
for _ in range(L):
    j,k = list(map(int,input().split()))
    j -= 1
    q.append((j,k))

NG = set()
while(q):
    now, HP = q.popleft()

    if(now in NG):continue
    NG.add(now)

    if(HP == 0):continue
    for i in edge[now]:
        q.append((i,HP-1))

q = deque([(0,0)])
INF = 10**18
dist = [INF for _ in range(N)]
while(q):
    v,now = q.popleft()

    if(now in NG):continue
    if(dist[now] <= v):continue
    dist[now] = v
    
    for i in edge[now]:
        q.append((v+1,i))

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