import java.util.*;

class Main {
	public static void main(String[] args){
		final Scanner sc = new Scanner(System.in);		
		final String str = sc.nextLine();
		StringBuilder sb = new StringBuilder();

		for(int i = 0; i < str.length(); i++){
			final char[] ca = str.toCharArray();
			final char c = ca[i];
			if('a' <= c && c <= 'z'){
				sb.append(String.valueOf(c).toUpperCase());
			} else if('A' <= c && c <= 'Z'){
				sb.append(String.valueOf(c).toLowerCase());
			} else {
				sb.append(String.valueOf(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