a=[]
while True:
    a1=input()
    if a1=='EOF':
        break
    else:
        a1=list(a1)
        for i in range(1,len(a1)):
            if a1[i] =='<':
                a1[i],a1[i-1]='1','1'
        a1=[j for j in a1 if j!='1']
        a.append(''.join(a1))

b=[]
while True:
    b1=input()
    if b1=='EOF':
        break
    else:
        b1=list(b1)
        for i in range(1,len(b1)):
            if b1[i] =='<':
                b1[i],b1[i-1]='1','1'
        b1=[j for j in b1 if j!='1']
        b.append(''.join(b1))

count=0
for i in range(len(a)):
    a2=list(a[i])
    b2=list(b[i])
    for j in range(min(len(a2),len(b2))):
        if a2[j]==b2[j]:
            count+=1
    
time=int(input())

print(round(count/time*60))