/***********************************************
* Name:       even_integers.cxx
* Author:     Leo Liberti
* Source:     GNU C++
* Purpose:    print out list of even numbers up to n
* Build:      c++ -o even_integers even_integers.cxx
* History:    120103 work started
***********************************************/

#include<iostream> 
#include<cstdlib>

int main(int argc, char** argv) {
  using namespace std;
  if (argc < 2) {
    cerr << argv[0] << ": prints list of even integers" << endl;
    cerr << argv[0] << ": error: syntax is " << argv[0] << " n" << endl;
    exit(1);
  }
  int n = atoi(argv[1]);
  if (n < 2) {
    cerr << argv[0] << ": error: n must be >= 2" << endl;
    exit(2);
  }
  for(int i = 2; i <= n; i += 2) {
    cout << i << endl;
  }
  return 0; 
}