6_3

#include<iostream>
using namespace std;
 
int ans;
int N, M;
bool areFriends[10][10];        
bool havePair[10];                
 
void counting(int n){
    bool finished = true;        
    int first = -1;        
    for (int i = 0; i < N; i++){
        if (!havePair[i])
        {
            finished = false;
            first = i;            
            break;
        }
    }
 
    if (finished){
        ans += 1;
        return;
    }
 
    for (int j = first+1; j < N; j++){
        if (!havePair[first] && !havePair[j] && areFriends[first][j]){
            havePair[first] = true;
            havePair[j] = true;
            counting(n+1);
            havePair[first] = false;
            havePair[j] = false;
        }
    }
   return;
}
 
int main()
{
    int tc;
    cin >> tc;
 
    for (int t = 1; t <= tc; t++){
        ans = 0;
        for (int i = 0; i < 10; i++){
            havePair[i] = false;
            for (int j = 0; j < 10; j++){
                areFriends[i][j] = false;
            }
        } 
        cin >> N >> M; 
        for (int i = 0; i < M; i++){
            int a, b;
            cin >> a >> b;
            areFriends[a][b] = true;
            areFriends[b][a] = true;
        } 
        counting(0); 
        cout << ans << endl;
    } 
    return 0;
}