#include<stdio.h>
int students, rela[10][10], isPair[10], count = 0;

int pat() {
    int i, first = -1;
    for (i = 0; i < students; i++) {
        if (isPair[i] == 0) {
            first = i;
            break;
        }
    }
    if (first == -1) {
        count++;
        return 0;
    }
    for (i = first + 1; i < students; i++) {
        if (isPair[i] == 0) {
            if (rela[first][i] == 1) {
                isPair[first] = 1;
                isPair[i] = 1;
                pat();
                isPair[i] = 0; isPair[first] = 0;
            }
        }
    }
    return 0;
}
int main() {
    int i, j, a, b, pairs, q, nn;
    scanf("%d", &nn);
    for (q = 0; q < nn; q++) {
        count = 0;
        scanf("%d %d", &students, &pairs);
        for (i = 0; i < pairs; i++)
            isPair[i] = 0;
        for (i = 0; i < pairs; i++)
            for (j = 0; j < pairs; j++)
                rela[i][j] = 0;

        for (i = 0; i < pairs; i++) {
            scanf("%d %d", &a, &b);
            rela[a][b] = 1;
            rela[b][a] = 1;
        }
        pat();
        printf("%d\n", count);
    }
}