import java.io.*;
import java.util.*;

public class Main{
  public static void main(String[] args){
    Scanner sc=new Scanner(System.in);
    String s=sc.nextLine();
    char c[]=s.toCharArray();
    for(int i=0;i<s.length();i++){
      if(Character.isUpperCase(c[i])){
        c[i]=Character.toLowerCase(c[i]);
      }else if(Character.isLowerCase(c[i])){
        c[i]=Character.toUpperCase(c[i]);
      }
    }
    StringBuffer sb=new StringBuffer(new String(c));
    System.out.println(sb.toString());
  }
}


/tmp/hf-datasets-cache/medium/datasets/42704881117311-config-parquet-and-info-qiankunmu-Project_CodeNet-896c9d36/hub/datasets--qiankunmu--Project_CodeNet_Python800_and_Java250/snapshots/c899fde44a77ba1cc14973ed3de064e4ff3aadc7/Project_CodeNet_Java250.tar.gz