Using the above information, do part 2. Please pay attention to the bottom sentences.

Infix A+B A+B-C A*B-C A+B*C (A+B)*C Postfix: AB+ AB+C AB*C ABC*+ AB+C* AB+CD-/ ABC/+D AB*CDE/-+ A+B/C-D A*B+(C-D/E) A*B+C/D-E A B+CI(D-E) A (B+C/(D-E) AB*CDE-/+ ABCDE-/+* An infix expression can be defined as: | expression> | ( ) operator>- +|-1*|/ Each operand is one character long. Operators * and I have the same precedence while and-have the same precedence. However, and?have higher precedence than + and Order of precedence can be changed by enclosing the operands by a pair of parenthesis. Spaces between operand and operator are optional You should check whether the input string is a correct representation of an expression according to the above definition of , especially the balancing of pairs of parenthesis ( and)