#include<iostream>
#include<string>
#include<iomanip>
using namespace std;
int main(){
string s;
int temp;
while(getline(cin, s)){
int count[30] = {0};
for(int i = 0; i < s.length(); i++){
temp = s[i] - 97;
if(temp >= 0 && temp <= 26){
count[temp]++;
}
}
char ch;
for(int i = 0; i < 26; i++){
ch = (char)('a' + i);
cout<<ch<<":"<<count[i]<<endl;
}
cout<<endl;
}
}