Evaluate Reverse Polish Notation Expression

Given a valid mathematical expression in Reverse Polish Notation (RPN), compute and output its value as a floating point number.

The expression is provided as a single line of space-separated tokens. Operands are numbers (which may be negative) and operators are one of the following: +, -, *, or /.

The evaluation should follow the standard RPN rules where an operator applies to the two most recent operands on the stack. In case of division, perform floating-point division. It is guaranteed that the provided expression is valid and does not contain any division by zero.

Note: The result must be computed using standard arithmetic rules and printed as a floating point number.

inputFormat

The input consists of a single line read from standard input (stdin). This line contains a complete RPN expression, where tokens (operands and operators) are separated by spaces.

outputFormat

Output a single line to standard output (stdout) containing the result of evaluating the RPN expression as a floating point number.

3 4 +

7.0