#include <iostream> #include <cmath> #include <climits> int main() { long long n; std::cin >> n; if (n <= 0) { std::cout << 0 << std::endl; return 0; } long long root = static_cast<long long>(std::sqrt(n)); if (root * root < n) { root++; } std::cout << root * root << std::endl; return 0; }