import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
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(c[i]>=65 && c[i]<=90){
c[i]+=32;
}else{
c[i]-=32;
}
}
System.out.println(new String(c));
}
}
