#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;
}
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