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