import java.util.Arrays;
import java.util.Scanner;
public class Main {
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
int qianbisum = in.nextInt();
int[] a = new int[3];
int[] b = new int[3];
int sum=0;
int[] count = new int[3];
for(int i=0;i<3;i++){
a[i]=in.nextInt();
b[i]=in.nextInt();
if(qianbisum%a[i] != 0){
sum = (qianbisum/a[i]+1) * b[i];
}else{
sum = qianbisum/a[i] * b[i];
}
count[i] = sum;
}
Arrays.sort(count);
System.out.println(count[0]);
}
}