Estimating the folded figure of origami from the crease pattern is a simple problem when the target is flat-origami and we do not have to consider the overlap order of faces. But when we have to consider the order, the problem becomes much more difficult due to the physical constraint of paper. In this paper we propose a method to find all valid overlap orders of faces using a stack. We also propose a method to extract unique configurations of origami from the valid overlap orders by applying new matrix operations.