A certain company purchased 71 pieces of the same product, and the total price on the invoice was polluted and could not be read clearly, and it became □23.60 yuan. What is the number of this contamination.
某公司购买了71件同样的商品，发票上的总价有一个数字被污染而无法看清，成了□23.60元．这个被污染的数字是多少．
<result>8</result>