import java.util.Scanner;

public class Main {

	public static void main(String[] args) {

		String str="";
		String conv_str="";

		Scanner sc= new Scanner( System.in );
		str = sc.nextLine();

		for ( int i = 0 ; i < str.length() ; i++ ) {
			if(Character.isUpperCase(str.charAt(i))) {
				conv_str += String.valueOf(str.charAt(i)).toLowerCase();
			}else if(Character.isLowerCase(str.charAt(i))) {
				conv_str += String.valueOf(str.charAt(i)).toUpperCase();
			}else {
				conv_str += String.valueOf(str.charAt(i));
			}
		}

		System.out.println( conv_str );

		sc.close();
	}
}


/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