The physical education teacher bought 10 "champion brand" footballs with the money, which was still 42 yuan short. Later, he borrowed 1000 yuan from a friend and bought 31 "champion brand" footballs, which turned out to be 13 yuan more. How much money does the physical education teacher have around him?
体育老师身边的钱买10个"冠军牌"足球，还差42元，后来他向朋友借了1000元，买了31个"冠军牌"足球结果多了13元．体育老师原来身边有多少元？
<gadget id="calculator">1_000 - 13 - 42</gadget>
<output>945</output>

<gadget id="calculator">31 - 10</gadget>
<output>21</output>

<gadget id="calculator">945 / 21</gadget>
<output>45</output>

<gadget id="calculator">10 * 45</gadget>
<output>450</output>

<gadget id="calculator">450 - 42</gadget>
<output>408</output>

<result>408</result>