C1 = raw_input()
C2 = raw_input()

W_total = C1 + C2
score_list = [0]
score = 1

for i in range(0,len(W_total)-1):
    if W_total[i] == W_total[i+1] and W_total[i] == "o":
        score += 1
        score_list.append(score)
    else:
        score = 1
print max(score_list)