import java.util.Scanner;

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<c.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]);
		}

		StringBuilder sb = new StringBuilder(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