For this Question: Given a postfix expression, your task is to evaluate given expression.

Infix expression: The expression of the form a operator b. When an operator is in-between every pair of operands.
Postfix expression: The expression of the form a b operator. When an operator is followed for every pair of operands.

Valid operators are +, -, *, /. Each operand may be an integer or another expression.The first line denotes the size of the string(which contains number or operand in form of string) i.e. N.
The next line contains string. The string contains an integer called operand or any of the four operators (+ - * /)

Constraints:-
1 <= n <= 40
1<=number<=500
Output the value of arithmetic expression formed using reverse Polish Notation.Input 1:
5
2 1 + 3 *
Output 1:
9

Explaination 1:
    starting from backside:
    *: ( )*( )
    3: ()*(3)
    +: ( () + () )*(3)
    1: ( () + (1) )*(3)
    2: ( (2) + (1) )*(3)
    ((2)+(1))*(3) = 9
    
Input 2:
5
4 13 5 / +
Output 2:
6

Explanation 2:
    +: ()+()
    /: ()+(() / ())
    5: ()+(() / (5))
    1: ()+((13) / (5))
    4: (4)+((13) / (5))
    (4)+((13) / (5)) = 6, I have written this Solution Code: import java.io.*;
import java.util.*;



class Main {
	public static void main (String[] args)throws IOException {

        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        int t = Integer.parseInt(br.readLine());
		String str[] = br.readLine().split(" ");
        Stack <Integer> st = new Stack<>();
        for(int i=0;i<t;i++){
            char ch = str[i].charAt(0);
			if(Character.isDigit(ch)){
                st.push(Integer.parseInt(str[i]));
            }
            else{
				int str1 = st.pop();
				int str2 = st.pop();
				switch(ch) {
					case '+':
					st.push(str2+str1);
					break;

					case '-':
					st.push(str2- str1);
					break;

					case '/':
					st.push(str2/str1);
					break;

					case '*':
					st.push(str2*str1);
					break;
			    }
			}
		}
        System.out.println(st.peek());
	}
}, In this Programming Language: Java, Now tell me if this Code is compilable or not?