#include<bits/stdc++.h>
using namespace std;
#define int long long
int n,num[100005],p[100005];
double minn=200000005.0;
signed main(){
	//freopen(".in","r",stdin);
	//freopen(".out","w",stdout);
	ios::sync_with_stdio(false);
	cin.tie(0);
	cout.tie(0);
	
	cin>>n;
	for(int i=1;i<=3;i++){
		cin>>num[i]>>p[i];
		minn=min(minn,ceil(1.0*n/num[i])*p[i]);
	}
	cout<<minn;
	return 0;
}