Problem:
Score : 100 points

Problem Statement

An uppercase or lowercase English letter \alpha will be given as input.
If \alpha is uppercase, print A; if it is lowercase, print a.

Constraints

\alpha is an uppercase (A - Z) or lowercase (a - z) English letter.

Input

Input is given from Standard Input in the following format:

α

Output

If \alpha is uppercase, print A; if it is lowercase, print a.

Sample Input 1

B

Sample Output 1

A

B is uppercase, so we should print A.

Sample Input 2

a

Sample Output 2

a

a is lowercase, so we should print a.

Solution in JavaScript (Node.js 12.16.1) (judge verdict: Wrong Answer)

function main(input) {
  const isUpperCase = (str) => {
    let arr = str.match(/^[A-Z]+$/);
    return arr ? true : false;
  };
  if (isUpperCase(input)) {
    console.log("A");
    return;
  } else {
    console.log("a");
    return;
  }
}
main(require("fs").readFileSync("/dev/stdin", "utf8"));