#include<iostream>
using namespace std;
int main(){
	int n,a[3],b[3],c[3],min=100000000000000;
	cin>>n;
	for(int i=1;i<=3;i++){
		cin>>a[i]>>b[i];
	}
	for(int i=1;i<=3;i++){
		if(n%a[i]==0){
			if(n/a[i]+1*b[i]<min){
				min=n/a[i]+1*b[i];
			}
		}else{
			if((n/a[i]+1)*b[i]<min){
				min=(n/a[i]+1)*b[i];
			}
		}
	}
	cout<<min;
	return 0;
}