import java.io.*;
import java.util.Arrays;
class Main{
    public static void main(String[] args) throws IOException {
        int i;
        int[] n = new int[990];
        String str;
        BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
        str = in.readLine();
        char[] c = str.toCharArray();
        for(i=0;i<c.length;i++){
            if(Character.isUpperCase(c[i])){
                c[i] = Character.toLowerCase(c[i]);
            }
            else if(Character.isLowerCase(c[i])){
                c[i] = Character.toUpperCase(c[i]);
            }
        }
        System.out.println(c);   
        System.out.flush();
    }
}
/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