#include <iostream>
#include <string>

const std::string s = "yukicoder";

void solve() {
    while (true) {
        int x;
        std::cin >> x;
        if (x == 0) break;
        std::cout << s[x - 1] << "\n";
    }
}

int main() {
    std::cin.tie(nullptr);
    std::ios::sync_with_stdio(false);

    solve();

    return 0;
}