#include<bits/stdc++.h>
using namespace std;
int t,i,ls1,ls2,a;
string s;
stack<char>s1[1001],s2;
signed main() {
	ios::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
	while(getline(cin,s)) {
		i++;
		if(s=="EOF")break;
		for(int j=0; j<s.size(); j++){s1[i].push(s[j]);}
	}
	i=0;
	while(getline(cin,s)) {
		i++;
		if(s=="EOF")break;
		for(int j=0; j<s.size(); j++) {
			if(s[j]=='<'&&!s2.empty())s2.pop();
			else s2.push(s[j]);
		}
		ls1=s1[i].size();
		ls2=s2.size();
		if(ls1>ls2) {
			while(s1[i].size()>ls2)s1[i].pop();
		} else if(ls2>ls1) {
			while(s2.size()>ls1)s2.pop(); 
		}
		while(!s2.empty()) {
			if(s1[i].top()==s2.top())a++;
			s1[i].pop();
			s2.pop();
		}
	}
	cin>>t;
	cout<<int(a*60.0/t+0.5)<<endl;
	return 0;
}