#include <bits/stdc++.h> #define int long long #define pb push_back using namespace std; const int N=2e5+10; const int inf=1e18; const int mod=1e9+7; pair<int,int> r[N],c[N]; int cnt[38][38][38][38]; signed main() { ios_base::sync_with_stdio(NULL); cin.tie(NULL); int T=1; // cin>>T; while(T--) { int n,k; cin>>n>>k; string s[n+1]; for(int i=1;i<=n;i++) { cin>>s[i]; int ch1=0,ch2,ch3,ch4; if(s[i][0]>='a') ch1=s[i][0]-'a'+10; else ch1=s[i][0]-'0'; if(s[i][1]>='a') ch2=s[i][1]-'a'+10; else ch2=s[i][1]-'0'; if(s[i][2]>='a') ch3=s[i][2]-'a'+10; else ch3=s[i][2]-'0'; if(s[i][3]>='a') ch4=s[i][3]-'a'+10; else ch4=s[i][3]-'0'; cnt[ch1][ch2][ch3][38]++; cnt[ch1][ch2][38][ch4]++; cnt[ch1][38][ch3][ch4]++; cnt[38][ch2][ch3][ch4]++; // cout<<ch1<<' '<<ch2<<' '<<ch3<<' '<<ch4<<endl; } // if(n<=2000) { // int ans=0; // for(int i=1;i<=n;i++) { // for(int j=i+1;j<=n;j++) { // if(i==j) continue; // int cnt=0; // for(int l=0;l<4;l++) { // if(s[i][l]!=s[j][l]) cnt++; // } // if(cnt==k) ans++; // } // } // cout<<ans<<"\n"; // } int ans=0; for(int i=1;i<=n;i++) { int ch1=0,ch2,ch3,ch4; if(s[i][0]>='a') ch1=s[i][0]-'a'+10; else ch1=s[i][0]-'0'; if(s[i][1]>='a') ch2=s[i][1]-'a'+10; else ch2=s[i][1]-'0'; if(s[i][2]>='a') ch3=s[i][2]-'a'+10; else ch3=s[i][2]-'0'; if(s[i][3]>='a') ch4=s[i][3]-'a'+10; else ch4=s[i][3]-'0'; ans+=cnt[ch1][ch2][ch3][38]+ cnt[ch1][ch2][38][ch4]+ cnt[ch1][38][ch3][ch4]+ cnt[38][ch2][ch3][ch4]-4; } cout<<ans<<"\n"; } } // 1 2 3 4 5 6 7