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 C# (.NET Core 3.1.201) (judge verdict: Accepted)

using System;
using System.Collections.Generic;

class Program
{
  static void Main()
  {
    string _str = Console.ReadLine();
    var message = (IsUpperString(_str)) ? "A" : "a";
    Console.WriteLine(message);
  }
  
  static bool IsUpperString(string s)
{
    // 指定した文字列が大文字かどうかを判定します。
    if (string.IsNullOrEmpty(s)) { return false; }

    foreach (char c in s)
    {
        if (!Char.IsUpper(c))
        {
            return false;
        }
    }
    return true;
}
}