program Project2;
{$APPTYPE CONSOLE}
uses
  SysUtils;
type
  tt = record
    t1, t2, t3: integer;
  end;
var
  i, n, time, tek: integer;
  a: array[1..50] of tt;
begin
  readln(n);
  for i := 1 to n do
    readln(a[i].t1, a[i].t2, a[i].t3);

{  sort(1, n);}
//....a[1].t1<a[2].t1<.....<a[n].t1
  time := 0;
  tek := 0;
  for i := 1 to n do
  begin
    if tek >= a[i].t1 then
      tek := tek + a[i].t2
    else
      tek := a[i].t1 + a[i].t2;
    if tek > a[i].t3 then
    begin
      time :=time+ tek - a[i].t3;
      tek := a[i].t3;
    end
  end;
  writeln(time);
end.