Input
 The input contains only one test case including several lines.
Each line contains an operation to be calculated.
The number of operations will no more than 300000.

Sample Input
A+=B
A*=A
A+=A
B+=A
C+=B
D=B

请问这样的问题要怎么样解决输入。

求高手回答啊!!!

把要输入的东西先写在文件中，然后读入它，不要设计为用键盘敲的。