백준 1541번 잃어버린 괄호

https://www.acmicpc.net/problem/1541

package test;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.util.StringTokenizer;

public class BaekJoonQ1541_P211_Q36 {

	public static void main(String[] args) throws IOException {
		// TODO Auto-generated method stub
		BufferedReader br =new BufferedReader(new InputStreamReader(System.in));
		BufferedWriter bw =new BufferedWriter(new OutputStreamWriter(System.out));
		StringTokenizer st = new StringTokenizer(br.readLine(),"-");
		String arr[] = new String[st.countTokens()];
		
		int i=0;
		int sum=0;
		while(st.hasMoreElements()) {
			arr[i] = st.nextToken();
			++i;
		}
		
		
		for(int arrSize=0; arrSize<arr.length; arrSize++) {
			st = new StringTokenizer(arr[arrSize],"+");
			while(st.hasMoreTokens()) {
				if(arrSize==0) sum += Integer.parseInt(st.nextToken());
				else sum -= Integer.parseInt(st.nextToken());
			}
		}
		bw.write(sum+"");
		bw.flush();
		
	}

}