3SUM

import sys
inp = sys.stdin.read().split()

n = int(inp[0])


if n <3 :
    print("IMPOSSIBLE")
    exit()


x = int(inp[1])
ind=0
numbers = []
for i in inp[2:]:
    numbers.append((int(i),ind))
    ind+=1


snumbers = sorted(numbers,key=lambda x: x[0])
print(snumbers)
#snumbers = sorted([item for item in numbers if item[0] <x-1],key=lambda x: x[0],reverse=True)

#let's start with a naive approach
    
left = 0
#middle = n//2
right = n-1


while(left<right):
    #print(left,right)

    while(snumbers[left][0] + snumbers[right][0] >=x ):
        right -=1
    else :
        l = left
        r = right
        while(l<=r):
            mid = l + (r - l) //2
            total = snumbers[mid][0] + snumbers[left][0] + snumbers[right][0] 
            #print(f"total is {total} with {l,mid,r}")
            if total == x:
                print(snumbers[left][1]+1,snumbers[mid][1]+1,snumbers[right][1]+1)
                exit()
            elif total < x:
                l = mid+1
            else:
                r = mid-1
        left+=1
print("IMPOSSIBLE")
#print(ind)
'''
while(left<right):
    print(left,right)
    total = snumbers[left][0] + snumbers[middle][0] + snumbers[right][0]
    print(total)
    if total == x :
        print(f"{left} {middle} {right}")
        exit()
    elif total >x :
        right -=1
    else :
        #do binary earch between them
'''

Test 1

Verdict: ACCEPTED

Test 2

Verdict: WRONG ANSWER

Test 3

Verdict: WRONG ANSWER

Test 4

Verdict: WRONG ANSWER

Test 5

Verdict: WRONG ANSWER

Test 6

Verdict: WRONG ANSWER

Test 7

Verdict: WRONG ANSWER

Test 8

Verdict: WRONG ANSWER

Test 9

Verdict: WRONG ANSWER

Test 10

Verdict: WRONG ANSWER

Test 11

Verdict: WRONG ANSWER

Test 12

Verdict: WRONG ANSWER

Test 13

Verdict: WRONG ANSWER

Test 14

Verdict: WRONG ANSWER

Test 15

Verdict: WRONG ANSWER

Test 16

Verdict: WRONG ANSWER

Test 17

Verdict: WRONG ANSWER

Test 18

Verdict: WRONG ANSWER

Test 19

Verdict: WRONG ANSWER

Test 20

Verdict: WRONG ANSWER

Test 21

Verdict: WRONG ANSWER

Test 22

Verdict: WRONG ANSWER

Test 23

Verdict: ACCEPTED