import java.util.*;

public class Main {
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		String line =sc.nextLine();
		char[] ar = line.toCharArray();
		for(char ch:ar){
			if(ch>='A'&&ch<='Z'){
				System.out.printf("%c",ch+32);
			}else if(ch>='a'&&ch<='z'){
				System.out.printf("%c",ch-32);
			}else{
				System.out.print(ch);
			}
		}
		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