#include <iostream>
#include <string>
#include <algorithm>
#include <vector>

using namespace std;


int main() {
	// 定义二维数组
	vector<string> s1;
	vector<string> s2;
	int ans = 0, n;
	string s;

	// 范文输入
	while (1) {
		int in_put_cur = -1;
		getline(cin, s);
		if (s == "EOF") {
			break;
		}
		else {
			string tmp;
			in_put_cur++;
			for (int i = 0; i < s.size(); i++) {
				if (s[i] == '<' && !tmp.empty()) {
					tmp.pop_back();
				}
				else {
					tmp.push_back(s[i]);
				}
			}
			s1.push_back(tmp);
			tmp.clear();
		}
	}

	// 用户输入
	while (1) {
		getline(cin, s);
		if (s == "EOF") {
			break;
		}
		else {
			string tmp;
			for (int i = 0; i < s.size(); i++) {
				if (s[i] == '<' && !tmp.empty()) {
					tmp.pop_back();
				}
				else {
					tmp.push_back(s[i]);
				}
			}
			s2.push_back(tmp);
			tmp.clear();
		}
	}
	for (int i = 0; i < s1.size(); i++) {
		for (int j = 0; j < min(s1[i].size(), s2[i].size()); j++) {
			ans += s1[i][j] == s2[i][j];
		}
	}
	cin >> n;
	cout << int(ans * 60.0 / n + 0.5) << endl;
	return 0;
}