https://www.acmicpc.net/problem/11655
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
// 11655번 ROT13
public class boj_7_11655 {
public static void main(String[] args) throws IOException {
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
StringBuilder sb = new StringBuilder();
char[] rot13 = br.readLine().toCharArray();
for (int i = 0; i < rot13.length; i++) {
if (rot13[i] >= 'A' && rot13[i] <= 'Z') {
if (rot13[i] >= 'N') {
rot13[i] -= 13;
} else {
rot13[i] += 13;
}
} else if (rot13[i] >= 'a' && rot13[i] <= 'z') {
if (rot13[i] >= 'n') {
rot13[i] -= 13;
} else {
rot13[i] += 13;
}
}
}
for (char i : rot13)
sb.append(i);
System.out.println(sb);
}
}