int main(int argc, array argv)
{
    string longest = "";
    foreach(Stdio.stdin.line_iterator();; string line)
    {
        if( sizeof(indices(line) - indices(longest)))
        {
            while(!zero_type(remove_call_out(write)));

            longest = line;
            call_out(write, 0, line+"\n");
        }
        else if( !sizeof(indices(longest) - indices(line)))
        {
            call_out(write, 0, line+"\n");
        }
    }
    call_out(exit, 0.01, 0);
    return -1;
}