题解 | 小红的排列构造
# a1+1=2外,其他数字自身相加(奇+奇,偶+偶)均为偶数➡合数,因此只需处理a1 length = int(input()) if length <= 2: print(-1) else: nlist = [] for i in range(1,length+1): nlist.append(i) # 交换a1,a3位置 nlist[0],nlist[2] = nlist[2],nlist[0] for i in nlist: print(i, end=' ')