This is a dislocation arrangement problem, which can be calculated by dislocation arrangement formula, that is, dn = n! ( 1- 1/ 1! + 1/2! - 1/3! +……+(- 1)^n/n！ ), here as long as the n = 5 generation into the calculation, you can get the result. If you don't use formulas, let's discuss them in categories, which is more troublesome. We still suggest using the formula.