07. String Explosion

package bg.softuni.javafundamentals;

import java.util.Scanner;

public class E07StringExplosion2 {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        StringBuilder sb = new StringBuilder(scanner.nextLine());

        int strengthOfExplosion = 0;

        for (int i = 0; i < sb.length(); i++) {
            if (sb.charAt(i) == '>') {
                int a = Character.getNumericValue(sb.charAt(i + 1));
                strengthOfExplosion += a;
            } else {
                if (strengthOfExplosion > 0) {
                    sb.deleteCharAt(i);
                    strengthOfExplosion--;
                    i--; // return to the previous symbol
                }
            }
        }
        System.out.println(sb);
    }
}