use proconio::input;

fn main(){
  input!{
    mut sentence:String
  }
  sentence = sentence.to_lowercase();
  let mut output:Vec<char> = vec![];
  for (i, c) in sentence.bytes().enumerate(){
    let result:u8 = (c - b'a' -((i % 26) as u8 + 1)) % 26 + b'a';
    output.push(result as char);
  }

  println!("{}",output.iter().map(|x| x.to_string().to_uppercase()).collect::<String>());
}