Infix Evaluation

import java.io.*;
import java.util.*;

public class Main{
  

public static void main(String[] args) throws Exception {
    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    String exp = br.readLine();
    Stack<Character> operators = new Stack<>();
        Stack<Integer> operands = new Stack<>();
        for (int i=0;i<exp.length();i++){
            char ch = exp.charAt(i);
                if (ch == '('){
                    operators.push(ch);
                }else if (Character.isDigit(ch)){
                    operands.push(ch-'0');
                }else if (ch == ')'){
                while (operators.peek()!='('){
                char optor = operators.pop();
                int v2 = operands.pop();
                int v1 = operands.pop();
                int opv = operation(v1,v2,optor);
                operands.push(opv);
                }
                operators.pop();
                }
                else if (ch == '+' || ch=='-' || ch == '/' || ch == '*'){
while (operators.size()>0 && operators.peek() != '(' && precedence(ch)<= precedence(operators.peek())){
                char optor = operators.pop();
                int v2 = operands.pop();
                int v1 = operands.pop();
                int opv = operation(v1,v2,optor);
                operands.push(opv);
                    }
                operators.push(ch);
                }


        }
        while (operators.size() != 0){
            char optor = operators.pop();
            int v2 = operands.pop();
            int v1 = operands.pop();
            int opv = operation(v1,v2,optor);
            operands.push(opv);
        }
        System.out.println(operands.peek());

    }
    public static int precedence(char oprator){
        if(oprator =='+'){
            return 1;
        }else if(oprator =='-'){
            return 1;
        }else if(oprator =='*'){
            return 2;
        }else {
            return 2;
        }
    }
    public static int operation(int v1, int v2, char operator){
        if (operator == '+'){
            return v1+v2;
        }else if (operator == '-'){
            return v1-v2;
        }else if (operator == '*'){
            return v1*v2;
        }else {
            return v1/v2;
        }
 }
}