import java.util.Scanner;

public class Main{
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        String line = sc.nextLine();
        StringBuilder sb = new StringBuilder();

        for(int i = 0; i < line.length() ; i++){
            char now = line.charAt(i);
            if(Character.isUpperCase(now))      sb.append(Character.toLowerCase(now));
            else if(Character.isLowerCase(now)) sb.append(Character.toUpperCase(now));
            else                                sb.append(now);
        }

        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