using System;

public class Program
{
  static void Main()
  {
    string S = Console.ReadLine();
    char[] S_ = S.ToCharArray();
    string W = "";

    for (int i = 0; i < S_.Length; i++)
    {
      if (char.IsUpper(S_[i]))
      {
        S_[i] = char.ToLower(S_[i]);
      }
      else
      {
        S_[i] = char.ToUpper(S_[i]);
      }
    }

    W = new string(S_);
    Console.WriteLine(W);
  }
}