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: i32 = (c as i32 - b'a' as i32 - (i as i32 + 1)).rem_euclid(26) + b'a' as i32;
        output.push(result as u8 as char);
    }

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