Reverse Polish Notation

Given an expression in Reverse Polish Notation (postfix), evaluate the value of the expression. In Reverse Polish Notation, the operators follow their operands. For example, the expression 3 10 5 + * is equivalent to 3 * (10 + 5).

The expression is given as an array either integers or operators. So, for the expression [3, 10, 5, '+', '*'] you should return 45.

The result should be rounded to the nearest integer.