s = [[] for _ in range(21)]

n = int(input())

for _ in range(n):
    l = input().split()
    
    if l[0] == '0':
        s[int(l[1])] = l[3:]
    
    elif l[0] == '1':
        for j in range(1, 21):
            if l[1] in s[j]:
                print(j)
                s[j].remove(l[1])
                break
        else:
            print(-1)

    else:
        s[int(l[1])] = []