#include <iostream>
#include <vector>
#include <set>
#define rep(i, l, n) for (int i = (l); i < (n); i++)
using namespace std;
template <class T>	using V = vector<T>;

int toNum(string s) {
	int ret = 0;
	rep(i, 0, s.size()) {
		char c = s[i];
		ret |= (3 - (c - 'A')) << (i << 1);
	}
	return ret;
}


int main(void) {
	int N, K;	cin >> N >> K;
	V<int> vec(N);
	V<bool> mag(1 << (K << 1));
	rep(i, 0, N) {
		string s;	cin >> s;
		vec[i] = toNum(s);
		mag[vec[i]] = true;
	}

	V<bool> visited(1 << (K << 1));
	for (int sv : vec) {
		if (visited[sv] == true) {
			continue;
		}
		V<int> stk = { sv };
		while (stk.empty() == false) {
			int v = stk[stk.size() - 1];
			stk.pop_back();
			rep(i, 0, K) {
				int k = i << 1;
				if (((v >> k) & 3) == 0) {
					continue;
				}
				int nv = v - (1 << k);
				if (visited[nv] == true) {
					continue;
				}
				visited[nv] = true;
				stk.push_back(nv);
			}
		}
	}

	int ans = 0;
	for (int v : vec) {
		if (visited[v] == false) {
			continue;
		}
		ans++;
	}
	cout << ans << endl;

	return 0;
}