fn main() { let mut s = String::new(); std::io::stdin().read_line(&mut s).ok(); let chs: Vec = s.as_str().trim().chars().collect(); let mut res = String::with_capacity(chs.len()); for i in 0..chs.len() { let mut ch = chs[i] as u8; for _ in 0..(i as u8 % 26 + 1) { ch -= 1; if ch == 64 { ch = 90; } } res.push(ch as char); } println!("{}", res); }