#include <bits/stdc++.h>

using namespace std;

#define ll long long
#define FOR(i, m, n) for(int i = m; i < n; i++)

int main() {
    ll a, b;
    cin >> a >> b;

    ll imin = a / 3;
    if (a % 3 != 0) imin++;
    ll imax = b / 3;

    FOR(i, imin, imax + 1) cout << 3 * i << endl;
    return 0;
}