#include<cstdio>
int main(){
int pen,p1,p1y,p2,p2y,p3,p3y;
scanf("%d%d%d%d%d%d%d",&pen,&p1,&p1y,&p2,&p2y,&p3,&p3y);
long int p = p1,pp = p2,ppp = p3;
while(p < pen){
p += p1;
p1y += p1y;
}
while(pp<pen){
pp += p2;
p2y += p2y;
}
while(ppp<pen){
ppp += p3;
p3y += p3y;
}
if(p1y < p2y && p1y < p3y)
printf("%d",p1y);
else if(p2y < p1y && p2y < p3y)
printf("%d",p2y);
else
printf("%d",p3y);
return 0;
}