Building Teams

n,m = [int(x) for x in input().split()]
friendship = []
for i in range (n):
    friendship.append([])
group = [0 for i in range(n)]
list_to_test = [0]

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

def test_friendship():
    while list_to_test:
        people = list_to_test.pop()
        flag = False
        color = 0
        for friend in friendship[people]:
            if group[friend] != 0:
                
                if flag:
                    if  color != group[friend]:
                        return False
                color = group[friend]
                group[people] = 3 - group[friend]
                flag = True
            else : 
                list_to_test.append(friend)    
        if flag == False:
            group[people] = 1      
    return True
            
            

test_friendship()

i = 1
test = False
while i<n:
    if group[i] == 0:
        list_to_test.append(i)
        if test_friendship() == False:
            print("IMPOSSIBLE")
            test = True
            break
    i+=1
    
if not(test):
    car = ""
    for eleve in group:
        car+= str(eleve) + " "
    print(car)

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: ACCEPTED

Test 6

Verdict: TIME LIMIT EXCEEDED

Test 7

Verdict: TIME LIMIT EXCEEDED

Test 8

Verdict: TIME LIMIT EXCEEDED

Test 9

Verdict: TIME LIMIT EXCEEDED

Test 10

Verdict: ACCEPTED

Test 11

Verdict: ACCEPTED

Test 12

Verdict: WRONG ANSWER