import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

class Main{
  public static void main(String args[]) throws IOException{
   BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
   String line = br.readLine();
   String[] token = line.split("");


   for (int i = 0; i < token.length; i++){
	   if( Character.isUpperCase(line.charAt(i) )){
		   token[i] = token[i].toLowerCase();
	   }else if( Character.isLowerCase(line.charAt(i)) ){
		   token[i] = token[i].toUpperCase();
	   }
	   System.out.print(token[i]);
   }

   System.out.println();

  }
}
/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