from collections import deque
N, K, P = list(map(int, input().split()))
Barja = [deque()] * K
res = 0
for i in range(N):
    S = input().split()
    r = 0
    S[1], S[2] = int(S[1]), int(S[2])
    if S[0] == '+':
        Barja[S[1] - 1].append(S[2])
    elif len(Barja[S[1] - 1]) > 0 and Barja[S[1] - 1][-1] == S[2]:
        Barja[S[1] - 1].pop()
    else:
        res = False
        break
    for i in Barja:
        r += len(i)
    if r > res:
        res = r
if res:
    print(res)
else:
    print('Error')