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