Building Teams

n, m = map(int, input().split())

friendships = [[] for _ in range(n)]
groups = [0 for _ in range(n)]

def findandlabel(x, team):
    for friendship in friendships[x]:
        if groups[friendship] == groups[x]: 
            print("IMPOSSIBLE")
            return False
        if groups[friendship] == 0:
            groups[friendship] = 2 if groups[x] == 1 else 1
            team = not team
            bool = findandlabel(friendship, team)
            if not bool: return False
    return True


for i in range(m):
    a, b = [int(x) for x in input().split()]
    friendships[a-1].append(b-1)

# print(friendships)


for i in range(len(friendships)):
    team = True # True is two, false is one
    if groups[i] == 0: groups[i] = 1
    # print(groups)
    bool = findandlabel(i, team)        

if bool: print(" ".join(map(str, groups)))

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: WRONG ANSWER

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: WRONG ANSWER

Test 11

Verdict: WRONG ANSWER

Test 12

Verdict: WRONG ANSWER