#include <iostream>
#include <stdio.h>
#include <algorithm>
#include <string>
using namespace std;


int main()
{
	const int N = 10005;
	string text[N], input[N],s;
	int i = 0;
	while (1)
	{
		getline(cin, s);
		if (s == "EOF")
			break;
		for (char o : s)
		{
			if (o == '<')
				text[i].pop_back();
			if (o >= 'a' && o <= 'z' || o == ' ' || o >= '1' && o <= '9' || o == '.')
			{
				text[i].push_back(o);
			}
		}
		i++;
	}

	 int i1 = 0;

	while (1)
	{
		getline(cin, s);
		if (s == "EOF")
			break;
		for (char o : s)
		{
			if (o == '<')
				input[i1].pop_back();
			if (o >= 'a' && o <= 'z' || o == ' ' || o >= '1' && o <= '9' || o == '.')
			{
				input[i1].push_back(o);
			}
		}
		i1++;
	}

	int N1 = 0;
	int Time;
	scanf("%d", &Time);

	for (int o = 0; o < i; o++)
	{
		for (size_t p = 0; p < min(text[o].length(),input[o].length()); p++)
		{
			if (text[o][p] == input[o][p])
				N1++;
		}
	}

	double KPS;
	KPS = (N1 * 1.0 / Time) * 60;
	KPS += 0.5;
	printf("%d", (int)KPS);
}