var
  w, b, n, k, s : longint;

begin
  readln(w);
  readln(b);
  readln(n);
  k := 0;
  if (1 <= w) and (w <= 10000) then
    if (1 <= b) and (b <= 10000) then
      if (1 <= n) and (n <= 10000) then
        if w = b then
          s := w * 2
        else
          s := min(w,b) * 2 + 1;
  if n > s then
    write('NO')
  else
    write('YES')
end.