// "static void main" must be defined in a public class.
public class Main {
    public static void main(String[] args) {
        int[] arr = {1,2,3,5,10,20,35,100};
        
        int left = 0, right = arr.length - 1;
        int target = 4;
        
        while (left <= right) {
            int mid = left + (right - left) / 2;
            int num = arr[mid];
            
            System.out.printf("L: %d M: %d R: %d\n", left, mid, right);
            
            if (num == target) {
                System.out.printf("Target %d exists!\n", target);
                return;
            } else if (num < target) {
                left = mid + 1;
            } else {
                right = mid - 1;
            }
        }
        
        System.out.printf("Target %d does not exists!\n", target);
    }
}