#include <cstdlib>
#include <iostream>
#include <cmath>
// use the ctime library
#include <ctime>

using namespace std;

int main()
{
  // declare clock variables
  clock_t start,finish;
  // start the clock ticking
  start = clock();
  
  // start doing some calculations
  cout << "Starting calculation...\n";
  double sum=0.;
  for (int i=1; i<10000; i++)
  {
	for (int j=1; j<10000; j++)
	{
	  sum += exp(-double(i)/(j)) + sin(0.1*j) + sqrt(double(i)/double(j));
	}
  }
  // finished calculations

  // stop the clock
  finish = clock();
  // print out time to screen. Note that finish and start must be converted to double, and then divided by CLOCKS_PER_SEC to convert into seconds
  cout << " Sum = " << sum << " and time taken for calculation is " << double(finish - start)/CLOCKS_PER_SEC << endl;
 return 0;
}