var
  f, f1: text;
  a, b, c, k, l: integer;
  d:real;
  
  a1 := 1;
  b1 := 2;
  c1 := 3;

begin
  Assign(f, 'INPUT.TXT');
  reset(f);
  read(f, a);read(f, b);read(f, c);read(f, k);
  close(f);
  if (0 <= a) and (a <= 100) and (0 <= b) and (b <= 100) and (0 <= c) and (c <= 100) and (1 <= b) and (b <= 1000) then// первые условия 
  begin
    var число:=0;
    l := min(a, b);
    l := min(l, c);
    while True do
    begin
      if(a  > 0) and (b  > 0) and(c  > 0) then
      begin
      a:=a-1;b:=b-1;c:=c-1;
      число:=число+1;
      end
      else
      break;
    end;
    a:=число*a1;b:=число*b1;c:=число*c1;
    d:=int((a+b+c)/k);
    assign(f1,'OUTPUT.TXT');
    rewrite(f1);
    write(f1,d);
    close(f1);
  end
  
end.