#include <bits/stdc++.h>
using namespace std;
#define int long long
map<string, int> mp[16];
int f[4];
signed main(){
ios_base::sync_with_stdio(false);
cin.tie(0); cout.tie(0);
int n, k; cin >> n >> k;
for(int i = 0; i < n; i++){
string x; cin >> x;
for(int mask = 1; mask < (1 << 4) - 1; mask++){
string t = "";
for(int j = 0; j < 4; j++) if(mask & (1 << j)) t += x[j];
f[3 - __builtin_popcount(mask)] += mp[mask][t]++;
}
}
if(k == 1) cout << f[0];
if(k == 2) cout << f[1] - (f[0] * 3);
if(k == 3) cout << f[2] - (f[1] * 2 - f[0] * 3);
if(k == 4) cout << n * (n - 1) / 2 - (f[0] - f[1] + f[2]);
}
