import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.IOException;

class Main{

	public static void main(String[] args) throws IOException{

		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		StringBuilder sb = new StringBuilder();
		String input = br.readLine();

		for(int i = 0; i < input.length(); i++){

			char token = input.charAt(i);

			if(Character.isUpperCase(token)){
				sb.append(Character.toLowerCase(token));
			}else{
				sb.append(Character.toUpperCase(token));
			}

		}

		System.out.println(sb);

	}
}
/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