import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileReader;
import java.io.FileWriter;
public class Main {
public static void main(String[] argv) throws Exception {
BufferedReader br = new BufferedReader(new FileReader("in.txt"));
BufferedWriter bw = new BufferedWriter(new FileWriter("out.txt"));
int i;
do {
i = br.read();
if (i != -1) {
if (Character.isLowerCase((char) i))
bw.write(Character.toUpperCase((char) i));
else if (Character.isUpperCase((char) i))
bw.write(Character.toLowerCase((char) i));
else
bw.write((char) i);
}
} while (i != -1);
br.close();
bw.close();
}
}