n = int(input())

uleft = set(range(1, 9))
uright = set(range(1, 9))
lleft = set(range(1, 9))
lright = set(range(1, 9))

for _ in range(n):
    dental_problem = input().split()

    try:
        if dental_problem[1] == "m":
            if dental_problem[0][0] == "-":
                lleft.remove(int(dental_problem[0][1]))
            elif dental_problem[0][0] == "+":
                uleft.remove(int(dental_problem[0][1]))
            elif dental_problem[0][1] == "-":
                lright.remove(int(dental_problem[0][0]))
            elif dental_problem[0][1] == "+":
                uright.remove(int(dental_problem[0][0]))
        else:
            if dental_problem[0][0] == "+" or dental_problem[0][0] == "-":
                lleft = set()
                uleft = set()
            else:
                lright = set()
                uright = set()
    except KeyError:
        pass

if len(lleft) > 0 and len(uleft) > 0:
    print(0)
elif len(lright) > 0 and len(uright) > 0:
    print(1)
else:
    print(2)