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));
        char c[] = br.readLine().toCharArray();
        for(int i=0;i<c.length;i++){
            if(Character.isUpperCase(c[i])){
                c[i] = Character.toLowerCase(c[i]);
            }else{
                c[i] = Character.toUpperCase(c[i]);
            }
        }
        System.out.println(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