Description：

Solution：

Code：

#include<algorithm>

#include<iostream>

#include<cstdlib>

#include<cstdio>

#include<cmath>

#include<cctype>

#include<cstring>

using namespace std;

int n,m;

#define MAXN 251

int g[MAXN][MAXN];

#define MOD 10007

int power(int a,int b)

{

	int res = 1;

	while(b > 0)

	{

		if(b & 1)res = 1ll * res * a % MOD;

		a = 1ll * a * a % MOD;

		b = b >> 1;

	}

	return res;

}

int main()

{

	scanf("%d%d",&n,&m);

	int a,b;

	for(int i = 1;i <= m;++i)

	{

		scanf("%d%d",&a,&b);

		++g[a][a];--g[a][b];

	}

	int ans = 1;

	for(int i = 2;i <= n;++i)

	{

		for(int j = i;j <= n;++j)

		{

			if(g[j][i] != 0)

			{

				if(j != i)

				{

					for(int l = i;l <= n;++l)swap(g[i][l],g[j][l]);

					ans = 1ll * ans * (MOD - 1) % MOD;

				}

				break;

			}

		}

		for(int j = i + 1;j <= n;++j)

		{

			int ratio = 1ll * g[j][i] * power(g[i][i],MOD - 2) % MOD;

			for(int l = i;l <= n;++l)g[j][l] = (g[j][l] - 1ll * ratio * g[i][l] % MOD + MOD) % MOD;

		}

	}

	for(int i = 2;i <= n;++i)ans = 1ll * ans * g[i][i] % MOD;

	cout << ans << endl;

	return 0;

}