overloaded function resolution...

[Vedam Shashank]

There are 3 overloaded functions.
I would like to know why second is being called here, (on my compiler the second is being called).

 #include<iostream> 
using namespace std;

int func(short &a)
{
 return a + 1;
}

int func(int &a)
{
 return a + 2;
}

int func(long &a)
{
 return a + 3;
}


int main()
{
 int num = 0;
 std::cout << func(num) << std::endl;
}

Thanks in advance.

Regards
Shaq