import java.io.InputStreamReader;
import java.io.BufferedReader;
public class Main {

    public static void main(String[] args) throws Exception {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        String line = br.readLine();

        for (int i = 0; i < line.length(); i++) {
            char c = line.charAt(i);
            char out = c;
            if (c >= 'a' && c <= 'z') {
                out = (char) (c - ('a' - 'A'));
            } else if (c >= 'A' && c <= 'Z') {
                out = (char) (c + ('a' - 'A'));
            }
            System.out.print(out);
        }
        System.out.println();
    }
}

/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