3SUM

n,target = [int(x) for x in input().split()]


numbers = [(int(val), i + 1) for i, val in enumerate(input().split())]

numbers.sort()  

for i in range(n):
    targets = {} 

    for j in range(i+1, n):
        new_target = target-numbers[j][0]-numbers[i][0]
        if new_target in targets:
            print(numbers[i][1], targets[new_target], numbers[j][1])
            exit()
        targets[numbers[j][0]] = numbers[j][1]

print("IMPOSSIBLE")

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: ACCEPTED

Test 6

Verdict: ACCEPTED

Test 7

Verdict: ACCEPTED

Test 8

Verdict: ACCEPTED

Test 9

Verdict: ACCEPTED

Test 10

Verdict: ACCEPTED

Test 11

Verdict: ACCEPTED

Test 12

Verdict: ACCEPTED

Test 13

Verdict: ACCEPTED

Test 14

Verdict: ACCEPTED

Test 15

Verdict: ACCEPTED

Test 16

Verdict: ACCEPTED

Test 17

Verdict: ACCEPTED

Test 18

Verdict: ACCEPTED

Test 19

Verdict: ACCEPTED

Test 20

Verdict: ACCEPTED

Test 21

Verdict: TIME LIMIT EXCEEDED

Test 22

Verdict: ACCEPTED

Test 23

Verdict: ACCEPTED