#include <iostream>
template<typename T>
T sum(T x, T y, T a = 0.0, T b = 100.0) {
return (x + y + a + b);
}
int main() {
std::cout << sum(1.3, 2.8) << "\n";
std::cout << sum(1.3, 2.8, 3.4) << "\n";
std::cout << sum(1.3, 2.8, 3.4, 4.2) << "\n";
return 0;
}
/*
run:
104.1
107.5
11.7
*/