var x,y,z,a,r,s,j:longint;
    b,c,n,t,i:longint;
begin
  assign(input,'iepuri.in'); reset(input); readln(t);
  assign(output,'iepuri.out'); rewrite(output);
  for i:=1 to t do begin
    readln(x,y,z,a,b,c,n);
    for j:=4 to n do begin
      if j mod 3=1 then r:=z*a
                   else if j mod 3=2 then r:=y*b
                                     else if j mod 3=0 then r:=z*a;
    end;
    s:=s+r;
  end;
  writeln(s);
  close(input); close(output);
  end.