@Test
public void testBug1963731() throws Exception {

    SmilesParser sp = new SmilesParser(DefaultChemObjectBuilder.getInstance());
    IAtomContainer molecule = sp.parseSmiles("C(C1C(C(C(C(O1)O)N)O)O)O");
    int hcount = 0;
    for (int i = 0; i < molecule.getBondCount(); i++) {
        hcount += molecule.getAtom(i).getImplicitHydrogenCount();
    }
    Assert.assertEquals(13, hcount);
}