#include<bits/stdc++.h>
using namespace std;
string a[100001],b[100001];
int main(){
	int i1=0,i2=0;
	double t,ans=0;
	string s;
	while(s!="EOF"){
		i1++;
		getline(cin,s);
		a[i1]=s;
	}
	s="";
	while(s!="EOF"){
		i2++;
		getline(cin,s);
		b[i2]=s;
	}
	for(int i=1;i<min(i1,i2);i++){
		stack<char> x;
		for(int j=0;j<a[i].length();j++){
			if(a[i][j]=='<'&&x.size()!=0) x.pop();
			else x.push(a[i][j]);
		}
		a[i]="";
		while(x.size()!=0){
			a[i]+=x.top();
			x.pop();
		}
		reverse(a[i].begin(),a[i].end());
		for(int j=0;j<b[i].length();j++){
			if(b[i][j]=='<'&&x.size()!=0) x.pop();
			else if(b[i][j]=='<'&&x.size()==0) continue;
			else x.push(b[i][j]);
		}
		b[i]="";
		while(x.size()!=0){
			b[i]+=x.top();
			x.pop();
		}
		reverse(b[i].begin(),b[i].end());
	}
	for(int i=1;i<min(i1,i2);i++){
		for(int j=0;j<min(a[i].length(),b[i].length());j++){
			if(a[i][j]==b[i][j]) ans++;
		}
	}
	cin>>t;
	printf("%.0lf",ans/(t/60));
}