var
  n:integer;
 total:real;
  t:array[1..5000]of shortint;
  v:array[1..5000]of real;
procedure init;
 var
  I,b,j:integer;
  a:char;
  c:real;
 begin
  readln(N);
  for i:=1 to n do
   begin
    read(a);
    while a<>' ' do read(a);
    read(b);
    if b=1 then
     begin
      read(c);
      v[i]:=c;
      t[i]:=1;
      for j:=1 to i-1 do
       if t[j]=0 then
        begin
         total:=total+c;
         t[j]:=1;
         v[j]:=c;
        end else
        if t[j]=1 then
         begin
          if c>v[j] then
           begin
            write('NO');
            halt;
           end;
         end;
      total:=total+c;
     end else t[i]:=0;
     readln;
   end;
 end;

begin
 init;
 if total>100 then write('NO') else write('YES');
end.