public static int binarySearchHelper(int[] nums, int target, int start, int end){
		if(start + 1 < end){
			int mid = start + (end - start) / 2;
			if(nums[mid]==target){
				return binarySearchHelper(nums,target,start,mid);
			} else if (nums[mid] > target){
				return binarySearchHelper(nums, target, start, mid);
			} else if (nums[mid] < target){
				return binarySearchHelper(nums, target, mid, end);
			}
		} 
		if(nums[start]==target){
			return start;
		}
		if(nums[end]==target){
			return end;
		}
		return -1;
		
		
	}