/* Author: the_kalakar/infinity23
----ASEEM BARANWAL----*/
#include<bits/stdc++.h>
#define fastio ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);
using namespace std;
const int maxN = 1000001;
vector<int> G[maxN], vis(maxN), so(maxN);
int n;
inline void output(string x){cout << x << endl;}
void solve(){
cin >> n;
for(int i = 1; i <=n; i++){
G[i].clear();
vis[i] = 0;
}
int r, m, a, b; cin >> r >> m;
while(r--){
cin >> a >> b;
G[a].push_back(b);
G[b].push_back(a);
}
queue<int> q;
while(m--){
int k, s; cin >> k >> s;
q.push(k);
if(vis[k]){
output("No");
break;
}
vis[k] = 1, so[k] = k;
int curr = 0;
while(!q.empty() and curr < s){
int node = q.front(); q.pop();
for(int x: G[node]){
if(vis[x] and so[x] != k){
output("No");
return;
}
vis[x] = 1;
so[x] = k;
q.push(x);
}
curr++;
}
}
output("Yes");
}
int main(){
fastio
int t;cin>>t;
while(t--){
solve();
}
return 0;
}
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