// JavaScript source code
"use strict";

let myFunc = (input) => {
    input = input.split("\n");
    let temp = input[0];
    if (temp >= 'A' && temp <= 'Z') console.log('A');
    if (temp >= 'a' && temp <= 'z') console.log('a');
};

myFunc(require("fs").readFileSync("/dev/stdin", "utf8"));