#include <iostream>
#include <vector>
using namespace std;

bool couple[10][10] = { false };
int n;

int check_out(bool student[]) {
    int first = -1;
    
    for (int i = 0; i < n; i++)
    {
        if (student[i] == false) {
            first = i;
            break;
        }
    }
    if (first == -1)
        return 1;

    int ret = 0;
    for (int next = first + 1; next < n; next++) {
        if (student[next] == false && couple[first][next] == true)
        {
            student[first] = student[next] = true;
            ret += check_out(student);
            student[first] = student[next] = false;
        }
    }
    return ret;
}

int main() {
    int C;
    cin >> C;
    vector<int> answer;
    bool student[10] = { false };
    for (int i = 0; i < C; i++) {
        int m;
        cin >> n >> m;
        for (int j = 0; j < m; j++) {
            int a, b;
            cin >> a >> b;
            couple[a][b] = couple[b][a] = true;
        }
        answer.push_back(check_out(student));
    }
    for (int i = 0; i < answer.size(); i++)
        cout << answer[i] << "\n";
}

이게 왜 실행이 안되는건지 이해가 안되네요 ㅠㅠ