map = new Int32Array(26);
charA = 65, charZ = 90, chara = 97, charz = 122;

//str = require('fs').readFileSync('tmp', 'ascii'); // win
str = require('fs').readFileSync('/dev/stdin', 'ascii'); // linux

for (i in str) {
	c = str[i].charCodeAt();
	idx = (c <= charZ) ? (c - charA) : (c - chara);
	if (idx >= 0 && idx < 26) map[idx]++;
}

for (i = 0; i < 26; i++) {
	console.log("%s : %d", String.fromCharCode(chara + i), map[i]);
}