#include <bits/stdc++.h>
using namespace std;

int main() {
    int n, k;
    cin >> n >> k;

    vector<pair<int, int>> v(n);
    for(int i = 0; i < n; i++) {
        cin >> v[i].first;
        v[i].second = i;
    }
    sort(v.begin(), v.end());

    for(int i = 0; i < n; i++) {
        int L = i + 1, R = n - 1;
        while(L < R) {
            if(v[L].first + v[R].first + v[i].first == k) {
                cout << v[i].second + 1 << " " << v[L].second + 1 << " " << v[R].second + 1 << endl;
                return 0;

            }
            if(v[L].first + v[R].first + v[i].first > k) {
                R--;
            }
            else {
                L++;
            }
        }
    }
    cout << "IMPOSSIBLE" << endl;
       return 0;
}