#include <iostream>
using std::cout;

int* treble(int);

int main(void)
{
  int num = 5;
  int* ptr = 0;
  ptr = treble(num);
  cout << *ptr;
  return 0;
}

int* treble(int data)
{
  int a = 0;
  if (data >= 5) {
    int b = 3 * data;
    return &b;
  }
  return &a;
}