#include <iostream>
#include <vector>

#define rep(i,a,b) for(int i=(a);i<(b);i++)
#define pb push_back
using namespace std;

int bit_f[4] = { 1, 2, 4, 8 };

int search(vector<int> v, int cnt, int bf)
{
	if (v.size() < 3) {
		bf |= bit_f[cnt];
		return bf;
	}
	vector<int> _v = v;
	int f = 0;
	rep(i, 0, (int)v.size() - 2) {
		rep(j, i + 1, (int)v.size() - 1) {
			rep(k, j + 1, (int)v.size()) {
				_v = v;
				if ((v[j] > v[i] && v[j] > v[k]) || (v[j] < v[i] && v[j] < v[k])) {
					_v.erase(_v.begin() + k); _v.erase(_v.begin() + j); _v.erase(_v.begin() + i);
					f = 1;
					bf = search(_v, cnt+1, bf);
				}
			}
		}
	}
	if (!f) bf |= bit_f[cnt];
	return bf;
}

int main(void)
{
	int n, t, bf;
	vector<int> v, _v;
	cin >> n;
	rep(i, 0, n) {
		cin >> t;
		v.pb(t);
	}

	rep(i, 0, (int)v.size() - 2) {
		rep(j, i+1, (int)v.size() - 1) {
			rep(k, j+1, (int)v.size()) {
				bf = 0;
				_v = v;
				if ((v[j] > v[i] && v[j] > v[k]) || (v[j] < v[i] && v[j] < v[k])) {
					_v.erase(_v.begin() + k); _v.erase(_v.begin() + j); _v.erase(_v.begin() + i);

					bf = search(_v, 0, bf);

					if (bf == 1 || bf == 4) {
						printf("%d %d %d\n", i, j, k);
						return 0;
					}
				}
			}
		}
	}

	cout << -1 << endl;
	
	return 0;
}