Xiaohong's father deposits 1,000 yuan in the bank as a one-year lump sum deposit and withdrawal. The annual interest rate is 3.87%, and the interest tax is 5%. How much is the pre-tax interest when it matures?
小红的爸爸把1000元钱按一年期整存整取存入银行，年利率是3.87%，利息税是5%，到期时可得税前利息多少元．
<gadget id="calculator">3.87 / 100</gadget>
<output>0.0387</output>

<gadget id="calculator">1_000 * 0.0387 * 1</gadget>
<output>38.7</output>

<result>38.7</result>