1
n = int(input())
2
a = [int(x) for x in input().split()]
3
 
4
for i in range(n):
5
    j = (i + 1) % n
6
    k = (i + 2) % n
7
    if (a[i] % 2) != (a[j] % 2) and (a[i] % 2) != (a[k] % 2):
8
        print(i + 1)
9
        break
10