#include <bits/stdc++.h>
#pragma GCC target("avx,avx2,fma")
#pragma GCC optimize("Ofast,unroll-loops")
using namespace std;
int n,m,k,q;
void solve(){
cin >> n >> k;
vector<string>v(n);
for(auto &to:v)cin >> to;
int res = 0;
if(n <= 2000 && false){
for(int i = 0;i<n;i++){
for(int j = i+1;j<n;j++){
int cnt = 0;
for(int l = 0;l<4;l++){
if(v[i][l] != v[j][l])cnt += 1;
}
if(cnt == k)res += 1;
}
}
}
else{
map<string,int>mp;
for(auto to:v)mp[to] += 1;
for(int i = 0;i<n;i++){
// mp[v[i]] -= 1;
for(int j = 0;j<4;j++){
char ch = v[i][j];
for(int l = 0;l<=9;l++){
char rep = (l+'0');
if(ch == rep)continue;
v[i][j] = rep;
res += mp[v[i]];
}
for(int l = 0;l<26;l++){
char rep = (l+'a');
if(ch == rep)continue;
v[i][j] = rep;
res += mp[v[i]];
}
v[i][j] = ch;
}
mp[v[i]] -= 1;
}
// res /= 2;
}
cout << res << "\n";
}
/*
*/
signed main()
{
// freopen("seq.in", "r", stdin);
// freopen("seq.out", "w", stdout);
ios_base::sync_with_stdio(0);cin.tie(NULL);cout.tie(NULL);
int tt=1;//cin>>tt;
while(tt--)solve();
}
