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: Runtime Error)

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApp2
{
    class Program
    {
        static void Main()
        {
            var a = int.Parse(Console.ReadLine());
            var X = Console.ReadLine().Split(' ').Select(x => int.Parse(x)).OrderBy(x =>x).ToArray();
            //var X = Console.ReadLine().Split(' ');
            var Q = int.Parse(Console.ReadLine());

            var b = new int[Q];
            var c = new int[Q];
            
            
            for (int i = 0; i < Q; i++)
            {
                int ans = 0;
                var z = Console.ReadLine().Split(' ').Select(x => int.Parse(x)).ToArray();
                b[i] = z[0];
                c[i] = z[1];
                

                for (int k = 0; k < X.Count(); k++)
                {
                    if (X[k] == b[i])
                    {
                        X[k] = c[i];
                    }

                    ans += X[k];
                }

                Console.WriteLine(ans);
            }
        }
    }
}