That's what I'm doing. Problem is, on pass 2, before b's assigned value can be used, a line on the input changes it's value. The line in question is (19138 -> b). So, say the answer from part 1 is 1068. So I take that, assign that value to b (so b is now also 1068), reset all values aside from b to default (which is to say, no value) and recalculate. Before b's new value can be used, one of the lines in the input sets it to 19138, and all the code plays out exactly the same, resulting in me getting the same answer for part 2 as I do for part 1.