Need help with tha Java code for this

Write a program that converts an infix (fully parenthesized) expression to a prefix expression. Like you know, the terms "in" and "pre" are according with the operator's position. The program will have to handle only the binary operators +,-, *, /, ^. parenthesis, letters and numbers. An example would be an expression like: (((A*B)+(2*(CA3))/(2*A)) The program must convert this expression (infix) to the prefix expression: /+*AB*2AC3*2A All expressions of the test cases are expressions with valid syntax. Input Read input from a file "in1.txt". The first line of input is an integer N (N