#include <iostream>
#include <vector>
#include <cstdio>
#include <sstream>
#include <map>
#include <string>
#include <algorithm>
#include <queue>
#include <cmath>
#include <set>
using namespace std;

int main(){
	long long a,b;
	cin >> a >> b;
	for(; a<=b; a++){
		if(a%3 == 0) cout << a << endl;
	}
	return 0;
}