include "iostream"

using namespace std; int main(){

int n;
cin>>n;
int a1,a2;
int b1,b2;
int c1,c2;
cin>>a1>>a2;
cin>>b1>>b2;
cin>>c1>>c2;
int s1 = double (n)/a1+0.99999;
int s2 = double (n)/b1+0.99999;
int s3 = double (n)/c1+0.99999;
int mon1 = s1*a2;
int mon2 = s2*b2;
int mon3 = s3*c2;
int ans1 = min(mon1,mon2);
int ans = min(ans1,mon3);
cout<<ans;
return 0;

}