#include"bits/stdc++.h"

using namespace std;

const int N = 1e6 + 10;

int n, m, ans = 0;

unordered_map<string, int> mp;
string ss[200];
vector<int> vis(200, 0);

string make(string s1, string s2) {
	string s3;
	s3 += " ";
	for(int i = 1; i <= n; i++) {
		s3 += s1[s2[i] - '0'];
	}
	return s3;
}

void dfs(string s, int k) {
	if(mp[s]) return;
	//cout << s << "\n";
	ans++;
	mp[s] = 1;
	for(int i = k + 1; i <= m; i++) {
		if(vis[i]) continue;
		vis[i] = 1;
		dfs(make(s, ss[i]), i);
		vis[i] = 0;
	}
}

void solve() {
	cin >> n >> m;
	for(int i = 1; i <= m; i++) {
		ss[i] += " ";
		for(int j = 1; j <= n; j++) {
			string x;
			cin >> x;
			ss[i] += x;
		}
		//cout << ss[i] << "\n";
	}
	for(int i = 1; i <= m; i++) {
		vis[i] = 1;
		dfs(ss[i], i);
		vis[i] = 0;
	}
	cout << ans << "\n";
}

int main() {
	ios::sync_with_stdio(0);
	cin.tie(0), cout.tie(0);
	solve();
	return 0;
}