from collections import deque
import sys
read = sys.stdin.readline
 
T = int(read())
for _ in range(T):
    N, R, M = map(int, read().split())
    graph = [[] for _ in range(N)]
    for _ in range(R):
        a, b = map(int, read().split())
        #przesuniecie bo indeksowanie jest od 1
        a-=1
        b-=1
        graph[a].append(b)
        graph[b].append(a)
 
    soldiers = []
    for _ in range(M):
        K, S = map(int, read().split())
        soldiers.append((K-1, S))
 
    def multi_source_bfs(sources,n,G):
        visited_by = [-1] * n
        q = deque()
        for index, (s, reach) in enumerate(sources):
            q.append((reach-1,s,index))
            visited_by[s] = index
        while q:
            r, v, id = q.popleft()
            #pomin jesli r < 0
            if r < 0:
                continue
            for u in G[v]:
                if visited_by[u] == -1:
                    visited_by[u] = id
                    q.append((r-1,u,id))
                elif visited_by[u] != id:
                    return False
        return True
 
    if multi_source_bfs(soldiers,N,graph):
        print("Yes")
    else:
        print("No")
 

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

MQozIDIgMwoxIDIKMiAzCjEgMAoyIDAKMyAw

1
3 2 3
1 2
2 3
1 0
2 0
3 0