Reverse Polish Notation Evaluator

You are given an expression in Reverse Polish Notation (RPN). In this notation, every operator follows all of its operands. For example, the expression 3 4 + is equivalent to 3 + 4 in conventional notation. Your task is to evaluate the RPN expression and output the integer result.

The expression is composed of integers and the operators \(+, -, \times, \div\). Note that division between two integers should truncate toward zero. It is guaranteed that the provided expression is valid and will result in a single integer value.

Example:

• Input: 3 4 +
• Output: 7

inputFormat

The input consists of a single line containing a valid Reverse Polish Notation expression. Tokens in the expression are separated by single spaces.

Each token is either an integer or one of the operators: +, -, *, or /.

outputFormat

Output the integer result after evaluating the RPN expression. The result should be printed to the standard output.

3 4 +

7