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

public class Main {
	public static void main(String[] args) throws IOException {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		char[] c = br.readLine().toCharArray();
		for (int i = 0; i < c.length; i++) {
			if (65 <= c[i] && c[i] <= 90) c[i] += 32;
			else if (97 <= c[i] && c[i] <= 122) 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