import java.io.*;

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