// ============================================== // Library // ============================================== #define _CRT_SECURE_NO_WARNINGS // When you are using the gcc compiler, you need only the following lines. // #include // When you are using other compilers, you need the following line instead. #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include using namespace std; // competitive macro #define FOR(i, a, b) for (int i = (a); i < (b); i++) #define RFOR(i, a, b) for (int i = (b) - 1; i >= (a); i--) #define REP(i, n) for (int i = 0; i < (n); i++) #define RREP(i ,n) for (int i = (n) - 1; i >= 0; i--) //#define LL long long typedef long long LL; typedef long long ll; //#define ULL unsigned long long typedef unsigned long long ULL; typedef unsigned long long ull; // const const ULL mod = 1000000007; // If you use this function, "cin" speeds up. // However, you can not mix "cin" and "scanf", "cout" and "printf". void fastIOS() { cin.tie(0); ios::sync_with_stdio(false); } // ============================================== // ============================================== int main() { fastIOS(); int n, m; cin >> n >> m; vector> mat(n, vector(n, 0)); REP(i, m) { int x, y; cin >> x >> y; mat[x][y] = mat[y][x] = 1; } int cnt = 0; REP(i, n) { FOR(j, i + 1, n) { FOR(k, j + 1, n) { FOR(l, k + 1, n) { int d1 = mat[i][j] + mat[i][k] + mat[i][l]; int d2 = mat[j][i] + mat[j][k] + mat[j][l]; int d3 = mat[k][i] + mat[k][j] + mat[k][l]; int d4 = mat[l][i] + mat[l][j] + mat[l][k]; if (d1 == 2 && d2 == 2 && d3 == 2 && d4 == 2) cnt++; } } } } cout << cnt << "\n"; }