c=input()
list=[]
for i in range(7):
    list.append(c[i])
    i=i+1
c=input()
for i in range(7):
    list.append(c[i])
    i=i+1
#print(list)    
c=0
o="o"
x="x"
olist=[]

for i in range(14):
    if list[i]==x:
        olist.append(c)
        c=0
    elif list[i]==o:
        c=c+1
    i=i+1    
olist.append(c)

print(max(olist))