# 2016.2.10 kadmatu
N = int(raw_input())
K = map(int, raw_input().split())
flag = -1
# flag = -1 D lose
# flag =  1 D win
if 3 <= N <= 12:
    for i in range(0, N-2):
        for j in range(i+1, N-1):
            for k in range(j+1, N):
                ch = (K[k] - K[j]) * (K[j] - K[i])
                if ch < 0 and flag != 1:
                    a = i
                    b = j
                    c = k
                    KK = []
                    KK += K
                    KK.pop(k)
                    KK.pop(j)
                    KK.pop(i)
                    flag = 1
                    if 5 < N <= 12:
                        for ii in range(0,len(KK)-2):
                            for jj in range(ii+1, len(KK)-1):
                                for kk in range(jj+1, len(KK)):
                                    ch = (KK[kk] - KK[jj]) * (KK[jj] - KK[ii])
                                    if ch < 0 and flag != -1:
                                        aa = ii
                                        bb = jj
                                        cc = kk
                                        KKK = []
                                        KKK += KK
                                        KKK.pop(kk)
                                        KKK.pop(jj)
                                        KKK.pop(ii)
                                        flag = -1
                                        if 8 < N <= 12:
                                            for iii in range(0,len(KKK)-2):
                                                for jjj in range(iii+1, len(KKK)-1):
                                                    for kkk in range(jjj+1, len(KKK)):
                                                        ch = (KKK[kkk] - KKK[jjj]) * (KKK[jjj] - KKK[iii])
                                                        if ch < 0 and flag != 1:
                                                            aaa = iii
                                                            bbb = jjj
                                                            ccc = kkk
                                                            KKKK = []
                                                            KKKK += KKK
                                                            KKKK.pop(kkk)
                                                            KKKK.pop(jjj)
                                                            KKKK.pop(iii)
                                                            flag = 1
                                                            if N == 12:
                                                                ch = (KKKK[2] - KKKK[1]) * (KKKK[1] - KKKK[0])
                                                                if ch < 0:
                                                                    flag = -1
if flag == 1:
    print a, b, c
#    print "D", a, b, c
#    print "K=", KK
#    print "E", aa, bb, cc
#    print "K=", KKK
#    print "D", aaa, bbb, ccc
#    print "K=", KKKK
elif flag == -1:
    print "-1"