#include <iostream>
using namespace std;
int main() {
std::string s;
std::cin >> s;
if (s == "да") {
std::cout << "YES" << std::endl;
}
return 0;
}
I2luY2x1ZGUgPGlvc3RyZWFtPgp1c2luZyBuYW1lc3BhY2Ugc3RkOwoKaW50IG1haW4oKSB7CglzdGQ6OnN0cmluZyBzOwoJc3RkOjpjaW4gPj4gczsKCWlmIChzID09ICLQtNCwIikgewoJCXN0ZDo6Y291dCA8PCAiWUVTIiA8PCBzdGQ6OmVuZGw7Cgl9CglyZXR1cm4gMDsKfQ==