#include <iostream>
#include<bits/stdc++.h>
using namespace std;
int min1=INT_MAX,cnt=0;
int a[4]={};
int b[4]={};
void money(int n1){
	for(int i=1;i<=3;i++){
		if(n1>0){
			n1-=a[i];
			cnt+=b[i];
			money(n1); 	
		}else{
			min1=min(min1,cnt);
//			cout<<min1<<" "<<endl;
			cnt=0;
			break;
		}
	}
}
int main(){
/*
freopen (".in","r",stdin);
freopen (".out","w",stdout);
*/
int n;
cin>>n;
for(int i=1;i<=3;i++){
	cin>>a[i]>>b[i];
}
money(n);
cout<<min1;




/*
fclose(stdin);
fclose(stdout);
*/
	return 0;
}