#include <bits/stdc++.h>
#define FOR(i, x, y) for (int i = x; i < y; i++)
typedef long long ll;
using namespace std;
map<string, ll> cnt[16];
ll ans[5];
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
ll n, d;
cin >> n >> d;
FOR(i, 0, n) {
string s;
cin >> s;
FOR(j, 0, 16) {
string sub = "";
FOR(k, 0, 4) if (j & (1 << k)) sub += s[k];
cnt[j][sub]++;
}
}
FOR(i, 0, 16) {
ll contrib = 0;
for (pair<string, ll> j : cnt[i])
contrib += j.second * (j.second - 1) / 2;
ans[4 - __builtin_popcount(i)] += contrib;
}
if (d == 1) cout << ans[1] - ans[0];
else if (d == 2) cout << ans[2] - 3 * (ans[1] - ans[0]);
else if (d == 3) cout << ans[3] - 3 * (ans[2] + ans[1] - ans[0]);
else cout << ans[4] - ans[3] + ans[2] - ans[1] + ans[0];
return 0;
}
