Postfix Expression Evaluation 2

Interview

Time limit2sMemory limit128 MB

Summary

Evaluate a postfix expression using given operand values and print the result rounded to two decimal places.

Level: Easy3 of 10
Topics: Stack, String, Implementation
Solved: No attempts yet

Problem

You are given a postfix expression and the value corresponding to each operand. Write a program that evaluates the expression.

Input

The first line contains the number of operands N. (1 <= N <= 26)

The second line contains the postfix expression. Operands are uppercase English letters starting from A, using exactly the first N letters in order. The expression length does not exceed 100.

From the third line through the N + 2-th line, one value is given for each operand. The third line is the value of A, the fourth line is the value of B, and so on. Each value is a natural number no greater than 100.

For every given input, while evaluating the postfix expression from left to right, the final result and every intermediate result are between -2,000,000,000 and 2,000,000,000, inclusive.

Output

Print the computed result rounded to exactly two digits after the decimal point.

Examples2

Example 1
Input
```
5
ABC*+DE/-
1
2
3
4
5
```
Expected output
```
6.20
```
Example 2
Input
```
1
AA+A+
1
```
Expected output
```
3.00
```