#include <bits/stdc++.h>
using namespace std;

#define int ll
using ll = long long;

const int MOD = 1e9 + 7;

int32_t main() {
    cin.tie(0)->sync_with_stdio(0);

    int n; cin >> n;
    int k; cin >> k;
    vector<vector<int>> a(n);
    for (auto &v : a) {
        string s; cin >> s;
        v.resize(k);
        for (int i = 0; i < k; i++) {
            v[i] = s[i] - '0';
        }
    }


    auto f = [&] (vector<int>& v) {
        int ret = 0;
        for (int i = 0; i < v.size(); i++) {
            ret = ret * 5 + v[i];
        }
        return ret;
    };

    vector vis(25*25*25*25, 0);
    sort(a.rbegin(), a.rend());

    auto go = [&] (auto&& self, vector<int>& v) {
        if (vis[f(v)]) return;
        vis[f(v)] = 1;
        for (int i = 0; i < k; i++) {
            if (v[i] > 0) {
                v[i]--;
                self(self, v);
                v[i]++;
            }
        }
    };
    int ans = 0;
    for (auto v : a) {
        if (vis[f(v)]) ans++;
        go(go, v);
    }

    cout << ans << endl;
}