#include <bits/stdc++.h>
using namespace std;
#define int long long
#define sp << ' ' <<
#define nl << '\n'
int mask;
bool comp(string x, string y){
for(int i=0; i<4; ++i){
if(((1<<i)&mask) and x[i]!=y[i]) return x[i]<y[i];
}
return false;
}
bool equal(string x, string y){
return comp(x, y)==comp(y, x);
}
signed main(){
cin.tie(0)->sync_with_stdio(0);
int n, d, ans = 0; cin >> n >> d;
string a[n]; for(auto &i : a) cin >> i;
d = n-d;
for(mask=0; mask<16; ++mask){
int cnt = 0;
for(int i=0; i<4; ++i) if((1<<i)&mask) ++cnt;
if(cnt<d) continue;
sort(a, a+n, comp);
for(int i=0; i<n; ++i){
int j = i;
while(j+1<n and equal(a[i], a[j+1])) ++j;
ans += ((cnt-d)%2 ? -1 : 1) * ((j-i+1)*(j-i))/2;
i = j;
}
}
cout << ans;
}
