#include <bits/stdc++.h>

const int N = 324;

int V, E, K;
int G[N][N];

void work() {
    int i, u, v;
    memset(G, 0, sizeof G);
    scanf("%d%d%d", &V, &E, &K);
    for (i = 0; i < E; ++i) scanf("%d%d", &u, &v), ++G[u][v], ++G[v][u], ++G[u][u], ++G[v][v];
    if (E < K * (V - 1)) {puts("No"); return;}
    for (i = 1; i <= V; ++i) if (G[i][i] < K) {puts("No"); return;}
    puts("Yes");
}

int main() {
    int T;
    for (scanf("%d", &T); T; --T) work();
    return 0;
}