#include <iostream>
#include <vector>
#include <algorithm>

typedef long long ll;

using namespace std;

struct Elem {
    ll val;
    ll pos;
};

bool operator<(const Elem& lhs, const Elem& rhs) {
    return lhs.val < rhs.val;
}

int main() {
    ll n, x;
    cin >> n >> x;

    vector<Elem> a(n);
    for (ll i = 0; i < n; ++i) {
        ll value;
        cin >> value;
        a[i] = {value, i};
    }

    sort(a.begin(), a.end());

    for (ll i1 = 0; i1 < n; ++i1) {
        for (ll i2 = i1 + 3; i2 < n; ++i2) {
            ll part = a[i1].val + a[i2].val;
            ll left = i1 + 1;
            ll right = i2 - 1;
            while (left < right) {
                ll tmp_sum = (a[left].val + a[right].val + part);
                if (tmp_sum == x) {
                    vector<ll> indices = {
                            a[left].pos,
                            a[right].pos,
                            a[i1].pos,
                            a[i2].pos
                    };
                    sort(indices.begin(), indices.end());
                    for (auto index : indices) {
                        cout << index + 1 << " ";
                    }
                    return 0;
                } else if (tmp_sum < x) {
                    ++left;
                } else {
                    --right;
                }
            }
        }
    }

    cout << "IMPOSSIBLE" << endl;

    return 0;
}