#include <iostream>
#include <cmath>
unsigned int roundToMultipleOf(unsigned int number, unsigned int multipleOf) {
return multipleOf * floor(number / multipleOf);
}
int main() {
std::cout << roundToMultipleOf(9, 5) << "\n";
std::cout << roundToMultipleOf(19, 5) << "\n";
std::cout << roundToMultipleOf(71, 5) << "\n";
}
/*
run:
5
15
70
*/