#include <iostream>
#include <math.h>
using namespace std;

int main()
{
    int n;
    cin>>n;
    int amount[3];
    int money[3];
    int real_money[3];
    for (int i=0;i<3;i++){
        cin>>amount[i]>>money[i];
        real_money[i]=ceil(n/amount[i])*money[i];
    }
    int min=real_money[0];
    for (int i=0;i<3;i++){
        if (min>=real_money[i]){
            min=real_money[i];
        }
    }
    cout<<min;
    return 0;
}