构造大数运算类 +；-；*；/ 并测试。<br>1. 不考虑括号 <br>2. 输入数据最大长度为40 位,要捕获异常 <br>3. 不考虑输入小数部分,<br>4. 测试要完整,先输入两个数,可输出上面两个数的运算结果 <br>5. 需要输出商和余数-Construction of large numbers+-*/computing and test category. <br> 1. Not consider brackets <br> 2. Input data for the maximum length of 40, it is necessary to catch the exception <br> 3. Do not consider the importation of the fractional part, <br> 4. The test to complete, enter both the number of output above the results of both the number of computing　<br> 5. Required output and the balance