#include <iostream>


// Function prototype for a function that takes an integer and returns its double

int double_num(int x);


// Function prototype for a function that takes an integer and returns its triple

int triple_num(int x);


int main() {

  int num = 5;


  // Call the double_num function within the triple_num function

  int tripled_num = triple_num(double_num(num));

  std::cout << "The triple of the double of " << num << " is " << tripled_num << std::endl;


  return 0;

}


// Definition of the double_num function

int double_num(int x) {

  return 2 * x;

}


// Definition of the triple_num function

int triple_num(int x) {

  return 3 * x;

}


output : 

The triple of the double of 5 is 30