import sys

with sys.stdin as f:
    ncases = int(f.readline())
    for caseix in range(ncases):
        try:
            nflavours = int(f.readline())
            nclients = int(f.readline())
            preferences = []
            preferences_count = []
            preferences_index = [0 for _x in xrange(nclients)]
            flavour_match = [[] for _x in xrange(nflavours)]
            flavour = [0 for _x in xrange(nflavours)]
            malted = []
            for clientix in range(nclients):
                data = f.readline().strip().split(' ')
                preferences_count.append(int(data[0]))
                lst = data[1:]
                l = [int(lst[ix]) - 1 for ix in range(len(lst)) if ix%2==0]
                s = [int(lst[ix]) for ix in range(len(lst)) if ix%2==1]
                preference = list(zip(l,s))
                preference.sort(key=lambda p: p[1])
                preferences.append(preference)
                if len(preference) == 1 and preference[0][1] == 1:
                    malted.append(preference[0][0])
                else:
                    flavour_match[preference[0][0]].append(clientix)
            while len(malted) != 0:
                new_malted = []
                for x in malted:
                    if flavour[x] == 1:
                        continue
                    flavour[x] = 1
                    for client in flavour_match[x]:
                        preferences_index[client] = preferences_index[client] + 1
                        while preferences_index[client] < preferences_count[client]:
                            if preferences[client][preferences_index[client]][1] == 1:
                                new_malted.append(preferences[client][preferences_index[client]][0])
                                break
                            elif flavour[preferences[client][preferences_index[client]][0]] == 1:
                                preferences_index[client] = preferences_index[client] + 1
                                continue
                            flavour_match[preferences[client][preferences_index[client]][0]].append(client)
                            break
                        if preferences_index[client] >= preferences_count[client]:
                            raise Exception
                malted = new_malted
        except:
            print 'Case #{}: IMPOSSIBLE'.format(caseix +1)
        else:
            print 'Case #{}:'.format(caseix +1),
            for x in flavour:
                print x,
            print ""