using System;
using System.Collections.Generic;
using System.Linq;
using System.Text.RegularExpressions;
using static System.Console;

public class hello{
    public static void Main(){
        //yukikoder No.163 cAPSlOCK        
        var sum = "";//AZ 65 90   az 97  122
        
        var s = ReadLine().Trim();
        for(int i=0 ; i< s.Length;i++){
            if(s[i]<97 ){ //大文字のとき
                sum += Convert.ToChar(s[i]+32);
            }else{
                sum += Convert.ToChar(s[i]-32);
            }
        }
        WriteLine(sum);
    }
}