#include <bits/stdc++.h> 
 
using namespace std;  
 
typedef long long ll;  
typedef pair<int, int> ii;  
 
const int INF = 1e9;  
const ll LINF = 1e18;  
 
const int MOD = 1e9 + 7;   
 
void add(int& a, int b) {
	a += b; 
	if (a >= MOD) a -= MOD;
}
 
int n, m; 
int adj_mat[20][20]; 
 
int dp[1 << 20][20]; // dp[mask][v] = Số đường đi xuất phát từ thành phố 1 (Syrjälä), 
					 //               đi qua tất cả các thành phố có trong mask, mỗi thành phố đúng một lần 
					 //               và kết thúc tại thành phố v 
 
int main() {
	ios::sync_with_stdio(false); 
	cin.tie(nullptr); 	
	cin >> n >> m; 	
 
	for (int i = 0; i < m; i++) {
		int u, v; 
		cin >> u >> v; 
		--u, --v; 
		adj_mat[u][v]++; 
	}
 
	for (int mask = 0; mask < (1 << n); mask++) {
		for (int v = 0; v < n; v++) {
			int& cur = dp[mask][v]; 
			if (mask == (1 << v) && v == 0) {
				cur = 1; 
				continue; 
			}
			cur = 0;  
			if (!(mask & (1 << v))) continue; 
			for (int u = 0; u < n; u++) {
				int prev_mask = mask ^ (1 << v); 
				add(dp[mask][v], 1ll * dp[prev_mask][u] * adj_mat[u][v] % MOD); 
			}
		}
	}
 
	cout << dp[(1 << n) - 1][n - 1] << '\n'; 
}

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