#include<iostream>
#include<cmath>
using namespace std;
int main()
{
	int n;
	cin>>n;
	int a[2],b[2],c[2],mins=2e9;
	for(int i=0;i<3;i++)
	{
		cin>>a[i]>>b[i];
		int k=0;
		k=ceil((double)n/a[i]);
		c[i]=k*b[i];
		if(k*a[i]>=n)
		{
			mins=min(c[i],mins);
		}
	}
	cout<<mins;
	return 0;
}