C++ program tell you the cube of the number entered by the user

#include<iostream.h>
 int main()
{int cube(int);
int a;
cout<<"Enter a number to find : ";
cin>>a;
cout<<"Cube of a number is as under : "<<cube(a);
return 0;}

int cube(int m)
{
int mx=m;
mx=mx*mx*mx;
return mx;
}