#include<bits/stdc++.h>
using namespace std;

using ll = long long;

int main() {
    cin.tie(nullptr)->sync_with_stdio(false);

    string s;
    cin >> s;
    int n = s.size();
    string a(s.begin(), s.begin() + n / 2), b(s.begin() + n / 2, s.end());
    for (int c = 0; c < 2; ++c, swap(a, b)) {
        int sum = 0;
        for (auto x : a) sum += x - 'A';
        sum %= 26;
        for (auto& x : a) x = char((x - 'A' + sum) % 26 + 'A');
    }
    for (int i = 0; i < a.size(); ++i) {
        a[i] = char((a[i] - 'A' + b[i] - 'A') % 26 + 'A');
    }
    cout << a;
}