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

public class Main {

	public static void main(String[] args)throws IOException 
	{
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		StringBuilder sb = new StringBuilder();
		sb.append(br.readLine());
		
		for(int i=0; i<sb.length(); i++)
		{
			char chk = sb.charAt(i);
			if(Character.isUpperCase(chk))
			{
				chk = Character.toLowerCase(chk);
				sb.setCharAt(i, chk);
			}
			else if(Character.isLowerCase(chk))
			{
				chk = Character.toUpperCase(chk);
				sb.setCharAt(i, chk);
			}
		}
		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