This project requires you to write a program that imitates a simple desk calculator. Your calculator must be able to accept an infix expression which at least includes (, ), +, -, *, /, ％, and ^ (exponentiation operator, a^b = ab ). If the expression is legal, output its value, else output an error message.

Input Specification:



Your program must read test cases from a file “input.txt”. In the file there are several test cases, each occupies one line that contains an infix expression. Proceed until the end of the file.



Output Specification:



For each test case, output to a file “output.txt” in one line the value of that expression (accurate up to two decimal places), or an error message “ERROR IN INFIX NOTATION”.