/**
 * Author: AcFunction
 * Date:   2019-08-25 13:51:45
 * Email:  3486942970@qq.com
**/

#include <bits/stdc++.h>
#define ll long long
#define db double
#define PII pair <int, int> 
#define pb push_back 
#define fi first
#define se second

using namespace std;

const int INF = 1000000; 

int T, n, m, k;
int dis[305][305], deg[305]; 
 
int main() {
  scanf("%d", &T); 
  while(T --> 0) { int fla = 1; 
    scanf("%d %d %d", &n, &m, &k);
    
    for(int i = 1; i <= n; i++) 
      for(int j = 1; j <= n; j++) 
        dis[i][j] = 0; 
    for(int i = 1; i <= n; i++)
        dis[i][i] = 1, deg[i] = 0; 
    for(int i = 1; i <= m; i++) {
      int u, v; scanf("%d %d", &u, &v); 
      dis[u][v]++, dis[v][u]++; 
      deg[u]++, deg[v]++; 
    }
    if(m / (n - 1) < k) {
      puts("No"); continue ; 
    } 
    for(int i = 1; i <= n; i++) {
      if(deg[i] < k) {
        puts("No"); fla = 0; break ; 
      }
    }
    if(!fla) continue ; 
    for(int l = 1; l <= n; l++)
      for(int i = 1; i <= n; i++)
        for(int j = 1; j <= n; j++) {
          if(i != j && l != i && l != j) {
             dis[i][j] += dis[i][l] * dis[l][j]; 
             if(dis[i][j] > k) dis[i][j] = k; 
          }
        }
    for(int i = 1; i <= n; i++) {
      for(int j = 1; j <= n; j++) {
        if(i != j && dis[i][j] < k) {
          puts("No"); fla = 0; break; 
        }
      }
    }
    if(!fla) continue ; 
    puts("Yes"); 
  }
  return 0; 
}