#include <iostream>
int main() {
unsigned u = 0;
if (std::cin >> u) {
std::cout << u << std::endl;
} else {
std::cout << "KO\n";
}
}
I2luY2x1ZGUgPGlvc3RyZWFtPgoKaW50IG1haW4oKSB7Cgl1bnNpZ25lZCB1ID0gMDsKCQoJaWYgKHN0ZDo6Y2luID4+IHUpIHsKCQlzdGQ6OmNvdXQgPDwgdSA8PCBzdGQ6OmVuZGw7Cgl9IGVsc2UgewoJCXN0ZDo6Y291dCA8PCAiS09cbiI7Cgl9Cn0=