a = int(input())

b = [[0 for i in range(2*a-1)] for i in range(a)]

zhong =(2*a-1)//2

b[0][zhong] =1

for i in range(1,a):

for j in range(len(b[0])):

if j-1 <0 :

b[i][j]= b[i-1][j]+b[i-1][j+1]

elif j+1>=len(b[0]):

b[i][j] = b[i-1][j]+b[i-1][j-1]

else:

b[i][j] = b[i-1][j]+b[i-1][j-1]+b[i-1][j+1]

def abc(d):

for k in range(len(d)):

if d[k] %2 ==0:

return k+1

return -1

print(abc(b[-1]))

内存超限，还是要找规律，打印10行规律就出来，分别在2324位置

a = int(input()) if a ==1 or a ==2: print(-1) elif (a-2)%4 ==1: print(2) elif (a-2)%4 ==2: print(3) elif (a-2)%4 ==3: print(2) elif (a-2)%4 ==0: print(4)