There are 10 candles on the table, 4 are blown out by the wind for the first time, 3 are blown out by the second time, and no candles are blown out after the window is closed. How many candles are there at the end on the table?
桌上有10根蜡烛，第一次被风吹灭4根，第二次被吹灭3根，把窗户关好后再也没有蜡烛被吹灭．桌上最后有多少根蜡烛．
<gadget id="calculator">3 + 4</gadget>
<output>7</output>

<result>7</result>