#include<bits/stdc++.h>
using namespace std ;
int main () {
  char a ;
  int nul[26] = {} ;
  while(cin>>a){
    if(isupper(a)) a = tolower(a) ;
    nul[(int)a-'a'] ++ ;
  }
  for(int i = 0 ; i < 26 ; i++ ) {
    cout << char(i+'a') << " : " << nul[i] << endl ;
  }
}
