#include<iostream>
#include<iomanip>
#include<cmath>
#include<cstring>
#include<string>
#include<cstdio>
#include<algorithm>
#include<stack>
#include<queue>
#include<map>
#include<vector>
#include<list>
using namespace std;
double a,b[100][3],maxx=200000000;
int main(){
	cin>>a;
	for(int i=0;i<3;i++){
		cin>>b[i][0]>>b[i][1];
		if(ceil(a*1.0/b[i][0])*b[i][1]<maxx){
			maxx=ceil(a*1.0/b[i][0])*b[i][1];
		}
	}
	cout<<maxx;
	return 0;
}