#include <stdio.h>
#include "primes.h"

#define BEGIN 1000000
#define END   2000000

int even (int);
int odd (int);

void test_goldbachs_conjecture(int i){
  int j;
  for(j = 3; j <= i/2; j += 2)
    if (is_prime(j) && is_prime(i-j) && odd(j) && odd(i-j)){
      printf("%d = %d + %d\n", i, j, i-j);
      return;
    }
  printf("%d is not composable\n", i);
}

int main(void) {
  int i, start;

  start = even(BEGIN)? BEGIN : BEGIN + 1;
  for(i = start; i <= END; i += 2)
    test_goldbachs_conjecture(i);
    
  return 0;
}

int even(int i){
  return i%2 == 0;
}

int odd(int i){
  return !(even(i));
}