CODE

#include <iostream>

using namespace std;

// sol1
// Time Complexity: O(100)
int main(void) {
  for (int i = 1; i <= 100; ++i)
    if (!(i & 1)) printf("%d\n", i);
  return 0;
}

// sol2
// Time Complexity: O(50)
int main(void) {
  for (int i = 2; i <= 100; i += 2)
    printf("%d\n", i);
  return 0;
}