310-4.cpp

#include<bits/stdc++.h>
using namespace std;
typedef long long LL;
const LL N = 2e5 + 10, P = 131;
int n, t, m, book[11], f[11][11], ans = 0;
vector<int>v[11];
void dfs(int i)
{
	if (i > n)
	{
		for (int j = 1; j <= t; ++j)
			if (!v[j].size())return;
		++ans;
		return;
	}
	for (int j = 1; j <= t; ++j)
	{
		int flag = 0;
		for (auto k : v[j])
			flag |= f[i][k];
		if (!flag)
		{
			v[j].push_back(i);
			dfs(i + 1);
			v[j].pop_back();
		}
		if (!v[j].size())return;
	}
}
void solve()
{
	scanf("%d%d%d", &n, &t, &m);
	for (int i = 1; i <= m; ++i)
	{
		int x, y;
		scanf("%d%d", &x, &y);
		f[x][y] = f[y][x] = 1;
	}
	dfs(1);
	printf("%d\n", ans);
}
 
int main()
{
	int T = 1;
	//scanf("%d", &T);
	while (T--)
	{
		solve();
	}
	return 0;
}