#include <bits/stdc++.h> 
 
#define fst first 
#define snd second  
 
using namespace std;  
 
typedef long long ll;  
typedef pair<int, int> ii;  
 
const int INF = 1e9;  
const ll LINF = 1e18;  
 
const int N = 5e3 + 5; 
 
int n, x; 
ii a[N]; 
 
int main() {
	ios::sync_with_stdio(false); 
	cin.tie(nullptr); 	
	cin >> n >> x; 
	for (int i = 1; i <= n; i++) {
		cin >> a[i].fst; 
		a[i].snd = i;  
	}
 
	sort(a + 1, a + n + 1); 
 
	for (int i = 1; i <= n; i++) {
		for (int j = i + 1, k = n + 1; j <= n; j++) {
			// i < j < k
			// k là vị trí nhỏ nhất thoả mãn a[k] >= x - a[i] - a[j]
			while (k - 1 > j && a[k - 1].fst >= (x - a[i].fst) - a[j].fst) k--; 
			if (!(j < k && k <= n)) continue; 
			if (a[i].fst + a[j].fst + a[k].fst == x) {
				cout << a[i].snd << ' ' << a[j].snd << ' ' << a[k].snd << '\n'; 
				return 0;  
			}
		}
	}
 
	cout << "IMPOSSIBLE" << '\n'; 
}

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NCA4CjIgNyA1IDE=

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2 7 5 1