package alibaba;

/**

* Created by liuyang on 17/4/1.

*/

import java.util.Scanner;

public class Main {

public static void main(String[] args) {

Scanner in = new Scanner(System.in);

int maxQps = Integer.valueOf(in.nextLine());

final String[] rtList = in.nextLine().split(",");

final int requestNum = Integer.valueOf(in.nextLine());

final int threadNum = Integer.valueOf(in.nextLine());

System.out.println(doneTime(maxQps, rtList, requestNum, threadNum));

}

/**

* 如果使用最优的最大吞吐量负载均衡算法，按照最优模型多久能够处理完所有请求，单位毫秒。

*

* @return

*/

static long doneTime(int maxQps, String[] rtList, int requestNum, int threadNum) {

//TODO

int qpsSum = 0;

for (String str : rtList) {

int singleMaxQps = threadNum * 1000 / Integer.valueOf(str);

if (singleMaxQps > maxQps) {

qpsSum = qpsSum + maxQps;

} else {

qpsSum = qpsSum + singleMaxQps;

}

}

return requestNum / qpsSum * 1000;

}

}