#include<iostream>
#include<vector>
#include<algorithm>
using namespace std;
int main(){
    int a,x,y,n,result=0;
    vector<int>v;
    cin>>a;
    for(int i=1;i<=3;i++){
        cin>>x>>y;
        if(a%x!=0){
            n=a/x+1;
        }
        else{
            n=a/x;
        }
        result=n*y;
        v.push_back(result);
    }
    sort(v.begin(),v.end());
    cout<<v[0];
}