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

public class Main {

	public static void main(String[] args) {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		try {
			String str = br.readLine();
			if(str.length() > 1200) {
				
			}
			StringBuilder b1 = new StringBuilder(str);

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

				if( Character.isUpperCase(str.charAt(i))){ //Upper
				    b1.replace(i,i+1,String.valueOf(str.charAt(i)).toLowerCase() );
				}
				else {//Lower
				   b1.replace(i,i+1,String.valueOf(str.charAt(i)).toUpperCase() );
				}
			}
			String t = b1.toString();
			System.out.println(t);

		}catch(IOException e) {
			System.out.println("Exception : " + e);
		}
	}
}

/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