import sys
from typing import List, Tuple
import random

int1 = lambda x: int(x) - 1
# input = lambda: sys.stdin.readline().rstrip('\n')
ii = lambda: int(input())
vi = lambda: list(map(int, input().split()))
vi1 = lambda: list(map(int1, input().split()))


def dbg(*args, **kwargs):
    print(*(repr(arg) for arg in args), *(f'{k}: {repr(v)}' for k, v in kwargs.items()),
          sep='; ', file=sys.stderr, flush=True)


def main():
    def ik(a, b, c):
        return (a < b > c or a > b < c) and a != c

    n = ii()
    a = vi()
    ks = []
    for i in range(n):
        for j in range(i + 1, n):
            for k in range(j + 1, n):
                if ik(a[i], a[j], a[k]):
                    ks.append((1 << i) + (1 << j) + (1 << k))

    dp = [False] * (1 << n)
    for i in range(1 << n):
        for k in ks:
            if (i & k) == k and not dp[i - k]:
                dp[i] = True
                break

    for k in ks:
        if not dp[(1 << n) - 1 - k]:
            return [i for i in range(n) if (1 << i) & k != 0]
    return -1


def _start():
    if (ret := main()) is not None:
        print(*ret) if isinstance(ret, List) or isinstance(ret, Tuple) else print(ret)


if __name__ == '__main__':
    _start()