fn main() {
    let s = read::<String>();
    for (i, c) in s.chars().enumerate() {
        let c = c as usize;
        let m = (c - 65 + 26 * 40 - (i + 1)) % 26 + 65;
        let c = m as u8 as char;
        print!("{}", c);
    }
    println!("");
}

fn read<T: std::str::FromStr>() -> T {
    let mut s = String::new();
    std::io::stdin().read_line(&mut s).ok();
    s.trim().parse().ok().unwrap()
}

fn read_vec<T: std::str::FromStr>() -> Vec<T> {
    read::<String>().split_whitespace()
        .map(|e| e.parse().ok().unwrap()).collect()
}

fn read_vec2<T: std::str::FromStr>(n: u32) -> Vec<Vec<T>> {
    (0..n).map(|_| read_vec()).collect()
}