#include<stdio.h>

int main(){
	int c[26]={0},i;
    char ch;
	while((ch=getchar())!='\n')
	if(ch >= 'a' && ch<= 'z')
	      c[ch-'a']++;
	for(int i=0;i<=25;i++)
	 printf("%c:%d\n",i+'a',c[i]);
	return 0;
}