3SUM

# cook your dish here
n,x = map(int, input().split())
a = list(map(int, input().split()))

k = list(a)

k.sort()
s=[]
for i in range(n-2):
    t = k[i]
    l = i+1
    r = n-1
    while l< r:
        c = t +k[l]+k[r]
        if c == x:
            s=[a.index(t)+1, a.index(k[l])+1, a.index(k[r])+1]
            break
        elif c < x:
            l=l+ 1
        else:
            r =r- 1

if s:
    print(*s)
else:
    print("IMPOSSIBLE")

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

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: ACCEPTED

Test 11

Verdict: WRONG ANSWER

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: ACCEPTED

Test 22

Verdict: ACCEPTED

Test 23

Verdict: ACCEPTED