#include <iostream>
template<class T>
constexpr T pi = T(3.141592653589793238L);
int main() {
int i = pi<int>;
float f = pi<float>;
double d = pi<double>;
std::cout << i << "\n";
std::cout << f << "\n";
std::cout << d << "\n";
}
/*
run:
3
3.14159
3.14159
*/