#include <bits/stdc++.h>
#define fr(i, n, m) for(int i = (n); i < (m); i ++)
#define st first
#define nd second
#define all(x) begin(x), end(x)
#define pb push_back
#define all(x) begin(x), end(x)
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<int,int> pii;
const int mxn = 1e5+5;
const ll inf = 1e18;
const ld eps = 1e-13;
const ll mod = 1e9 + 9;
mt19937 _rand(time(0));
int n, k;
string s[mxn];
unordered_map<string, int> mapa;
ll ans = 0;
void process(int j){
fr(mask, 1, (1<<4)){
int bts = __builtin_popcount(mask);
if(bts < k) continue;
string ns = "$$$$";
fr(i, 0, 4){
if(mask&(1<<i)){
ns[i] = s[j][i];
}
}
int p = +1;
if((bts-k)%2){
p = -1;
}
ans += mapa[ns]*p;
}
fr(mask, 1, (1<<4)){
string ns = s[j];
fr(i, 0, 4){
if(mask&(1<<i)) continue;
ns[i] = '$';
}
mapa[ns] ++;
}
}
int main(){
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cin >> n >> k;
fr(i, 0, n){
cin >> s[i];
}
k = 4-k;
fr(i, 0, n)process(i);
if(k == 4){
cout<<ans<<endl;
return 0;
}
int ans2 = ans;
ans = 0;
mapa.clear();
k++;
fr(i, 0, n)process(i);
cout<<ans2-ans<<endl;
return 0;
}/*
1
3
2 3 -1*/
