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

typedef long long ll;
int main()
{
  int n;
  ll x;
  cin >> n >> x;

  pair<ll, int> niza[n];
  for(int i = 0; i < n; i++) {
      cin >> niza[i].first;
      niza[i].second = i;
  }
  sort(niza, niza + n);
  for(int k = 0; k < n; k++) {
    int i = k + 1, j = n - 1;
    while(i < j) {
      if(niza[i].first + niza[j].first + niza[k].first == x) {
        cout << niza[k].second + 1 << " " << niza[i].second + 1 << " " << niza[j].second + 1 << endl;
        return 0;
      }
      if(niza[i].first + niza[j].first + niza[k].first < x) {
        i++;
      }
      else {
        j--;
      }
    }
  }
  cout << "IMPOSSIBLE" << endl;

  return 0;
}