#include <bits/stdc++.h>
using namespace std;
using ll = long long;
const int mod = 1e9 + 7;
const int inf = (1 << 30) - 1;
const ll infll = (1LL << 61) - 1;

string s;

int main()
{
    cin >> s;
    int N = s.size();
    for (int i = 0; i < N; i++)
    {
        s[i] = ((s[i] - 'A' - (i + 1)) % 26 + 26) % 26 + 'A';
    }
    cout << s << endl;
}