#include <stdio.h>
int main(int argc, char const *argv[])
{
	int n1, n2;
	scanf ("%i %i", &n1, &n2);
	for (n1; n1<n2; ++n1){
		if (n1%2==0){
			printf("%i\n", n1);
		}
	}
	return 0;
}