import java.util.Iterator;
import java.util.List;
import java.util.Scanner;
public class Main{
	public static void main(String[]args) {
		Scanner input=new Scanner(System.in);
		List<String> x=new ArrayList<String>();
		List<String> y=new ArrayList<String>();
		for(String a=input.nextLine();!a.equals("EOF");a=input.nextLine()) {
			x.add(a);
		}
		
		for(String a=input.nextLine();!a.equals("EOF");a=input.nextLine()) {
			y.add(a);
		}
		int t=input.nextInt();
		int t0=0;

		Iterator<String> itx=x.iterator();
		Iterator<String> ity=y.iterator();
		while(itx.hasNext()&&ity.hasNext()) {
			char[] x1=itx.next().toCharArray();
			char[] y1=ity.next().toCharArray();
			itx.remove();
			ity.remove();
			for(int i=0;i<x1.length;i++) {
				if(x1[i]=='<'&&i!=0) {
					char[] xtem=new char[x1.length-2];
					for(int i0=0;i0<xtem.length;i0++) {
						if(i0<i-1)xtem[i0]=x1[i0];
						else if(i0>=i-1)xtem[i0]=x1[i0+2];
					}
					x1=xtem;
					i=0;
				}
			}
			for(int i=0;i<y1.length;i++) {
				if(y1[i]=='<'&&i!=0) {
					char[] ytem=new char[y1.length-2];
					for(int i0=0;i0<ytem.length;i0++) {
						if(i0<i-1)ytem[i0]=y1[i0];
						else if(i0>=i-1)ytem[i0]=y1[i0+2];
					}
					y1=ytem;
					i=0;
				}
			}
			//System.out.println(x1);
			//System.out.println(y1);
			for(int i=0;i<x1.length&&i<y1.length;i++) {
				if(x1[i]==y1[i])t0++;
			}
		}
		System.out.print(t0*60/t);
	}
}