program busses;

const inp:string='busses.in';
      out:string='busses.out';

var p:array[1..10]of integer;
    n,i,mon,min:integer;
    f:text;

procedure go(km,mon:integer);
 var i:integer;
 begin
  for i:=1 to 10 do
  begin
   if i+km<n then
    go(km+i,mon+p[i]) else
   begin
    if mon+p[i]<min then
     min:=mon+p[i];
    break;
   end;
  end;
 end;

begin
 assign(f,inp);
 reset(f);

 for i:=1 to 10 do
  read(f,p[i]);
 readln(f,n);

 close(f);

 min:=maxint;
 go(0,0);

 assign(f,out);
 rewrite(f);

 writeln(f,min);

 close(f);
end.