#include <iostream>
#include <typeinfo>
using namespace std;
double operator+(const int& a,const string& b){
return 3.4;
}
auto f(){
return 3.4;
}
auto sum(auto a, auto b){
return a + b;
}
int main(){
cout<< sum(1.0, string("hello")) <<endl;
cout<< sum(1, string("hello")) <<endl;
std::cout<< f() << std::endl;
}