If the natural number n makes the vertical addition n+(n+1)+(n+2) not produce carry phenomenon, then n is called "continuous number". For example, 12 is a "continuous number", because the vertical addition of 12+13+14 does not produce a carry phenomenon; and 13 is not a "continuous number". So how many "continuous numbers" do not exceed 1000?
若自然数n使得作竖式加法n+(n+1)+(n+2)不产生进位现象，便称n为"连绵数"．例如12是"连绵数"，因为12+13+14作竖式加法不产生进位现象；而13不是"连绵数"．那么不超过1000的"连绵数"共有多少个
<gadget id="calculator">3 * 4 * 4</gadget>
<output>48</output>

<gadget id="calculator">48 + 1</gadget>
<output>49</output>

<result>49</result>