题解 | #杨辉三角的变形#
杨辉三角的变形
https://www.nowcoder.com/practice/8ef655edf42d4e08b44be4d777edbf43
'''
关键：除了前2行，后边2，3，2，4
'''
n = int(input())
def f(n):
if n == 1 or n == 2:
return -1
elif n % 4 == 3:
return 2
elif n % 4 == 0:
return 3
elif n % 4 == 1:
return 2
elif n % 4 == 2:
return 4
print(f(n))
