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**Hayoota** Thank you!

I need help with one more question involving discrete math:

2)A hungry spider sits at one corner of a rectangular three-dimensional grid with 4 steps in every direction. In the opposite corner there is a juicy fly that cannot move. The spider can only move along the grid lines, that is right/left, up/down and front/back. Assuming that the spider in the upper left back corner is efficient and doesn't waste time on detours, in how many ways can it reach the fly in the lower right front corner?