"use strict";
main(require("fs").readFileSync("/dev/stdin", "utf8").replace(/\r?\n$/, "").split(/\r?\n/));

function main(lines){
	var str = lines.join(), a = "a".charCodeAt(), z = "z".charCodeAt();
	for(var n=a;n<=z;n++){
		var c = String.fromCharCode(n);
		console.log(c + " : " + (str.split(new RegExp(c, "i")).length-1));
	}
}