num_list = list(map(int, (input().split())))
num_list.sort()

A = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]

if 10 not in num_list:
    print(10)
elif 10 in num_list:
    dif_list = []
    for num, a in zip(num_list, A): #リストの各要素同士を引く
        dif = a - num
        dif_list.append(dif)
print(dif_list.index(-1)+1)