n = int(input())
K = list(map(int, input().split()))

def kado(a, b, c):
    if len({a, b, c}) != 3:
        return False
    return b in [max(a, b, c), min(a, b, c)]
    
lst = []
for i in range(n):
    for j in range(i + 1, n):
        for k in range(j + 1, n):
            if kado(K[i], K[j], K[k]):
                lst.append((1 << i) | (1 << j) | (1 << k))
                

g = [0] * (1 << n)
for bit in range(1 << n):
    mex = set()
    for l in lst:
        if bit | l == bit:
            mex.add(g[bit ^ l])
    i = 0
    while i in mex:
        i += 1
    g[bit] = i

if g[-1] == 0:
    print(-1)
else:
    for l in lst:
        if g[l ^ bit] == 0:
            ans = []
            for i in range(n):
                if l >> i & 1:
                    ans.append(i)
            print(*ans)
            break