function Main(input) {
    input = input.split("\n");
    const s = input[0];
    const al = "ABCDEFGHIJKLMNOPQRSTUVWXYZ".split("");
    let res = "";
    for (let i = 0; i < s.length; ++i) {
        let idx = al.indexOf(s[i]);
        idx -= i + 1;
        idx %= 26;
        if (idx < 0) idx += 26;
        res += al[idx];
    }
    console.log(res);
}
Main(require("fs").readFileSync("/dev/stdin", "utf8"));