#include <iostream>
#include <vector>
#include <algorithm>
#include <cmath>
#include <iomanip>
#include <stack>
#include <algorithm>
#include <string>
#include <map>
#include <iterator>
#include <set>
#include <queue>

using namespace std;

char solve(char c, int i) {

    int b = (c - 'A') - i;
    while (b < 0) {
        b += 26;
    }
    char res = (char) ('A' + b % 26);
    return res;

}


int main() {

    string S;
    cin >> S;
    string res;
    for (int i = 0; i < S.size(); ++i) {
        res += solve(S[i], i + 1);
    }

    cout << res << endl;

    return 0;

}