#include <bits/stdc++.h>
using namespace std;
string a[10010];
double pd(string x,string y){
	string w;
	for (int i = 0 ; i < x.size() ; i ++){
		if(x[i] == '<'){
			if(w.size()>0){
				w.erase(w.begin()+w.size()-1,w.begin()+w.size());
			}
		}else{
			w+=x[i];
		}
	}
	int ans = 0;
	for (int i = 0 ; i < min(w.size(),y.size()) ; i ++){
		if(w[i] == y[i]){
			ans ++;
		}
	}
	return ans;
}
int main(){
	//cout << pd("hello world.","heelo world.");
	//*
	int i = 1;
	getline(cin,a[i]);
    while(a[i] != "EOF"){
    	i++;
    	getline(cin,a[i]);
    	string w;
		for (int j = 0 ; j < a[i].size() ; j ++){
			if(a[i][j] == '<'){
				if(w.size()>0){
					w.erase(w.begin()+w.size()-1,w.begin()+w.size());
				}
			}else{
				w+=a[i][j];
			}
		}
		a[i] = w;
	}
	string s;
	double d = 0;
	for (int j = 1 ; j < i ; j ++){
		getline(cin,s);
		d+=pd(s,a[j]);
		//cout << pd(s,a[j]) << endl;//<<' '<< s  << '*'<< a[j] << endl;
	}
	cin >> s;
	double p;
	cin >> p;
	//cout << d << endl;
	cout << (int)(d*(60/p)+0.5);
	//*/
    return 0;
}