import java.util.Scanner;

public class Main{
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		String tmp = sc.nextLine();
		char[] c = tmp.toCharArray();
		for(int i = 0; i < c.length; i++){
			if(c[i] >= 'a' && c[i] <= 'z' ){
				c[i] -= 32;
			}else if(c[i] >= 'A' && c[i] <= 'Z'){
				c[i] += 32;
			}
		}
		System.out.println(String.valueOf(c));
	}
}
/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