import java.util.*;

public class Main{
	public static void main(String[] args){

		Scanner scan = new Scanner(System.in);
		String str = scan.nextLine();
		StringBuilder sb = new StringBuilder();
		String s = null;
		String t = null;
		for(int i = 0; i < str.length(); i++){
			if(Character.isUpperCase(str.charAt(i))){
				s = String.valueOf(str.charAt(i)).toLowerCase();
			} else if(Character.isLowerCase(str.charAt(i))){
				s = String.valueOf(str.charAt(i)).toUpperCase();
			} else{
				s = String.valueOf(str.charAt(i));
			}
			sb.append(s);
		}
		t = sb.toString();
		System.out.println(t);
	}
}
/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