#include <iostream>
#include <cstdint>

template<class T>
T AddFor(T To,T Step = 1){
	T R = T();
	for (T i = T(); i <= To; i += Step){
		R += i;
	}
	return R;
}

int main(){
	auto R = AddFor<std::uint64_t>(100000);

	std::cout << R << std::endl;

	return 0;
}