There are 80 actors in a song and dance troupe, and there is at least one actress among any 5 of them, so how many actresses are there in this song and dance troupe?
某歌舞团有80位演员，其中任意5人中至少有一位女演员，那么这个歌舞团中至少有多少位女演员．
<gadget id="calculator">5 - 1</gadget>
<output>4</output>

<gadget id="calculator">80 - 4</gadget>
<output>76</output>

<result>76</result>