
    In a professional networking platform, given a sorted list of professional IDs where professionals with shared career interests appear in pairs, write a function to identify the one professional with a unique specialization. The professional IDs are pre-sorted, and all professionals except one have found their career interest match within the 50-mile radius.
    

    
def search(arr):
    """
    In a professional networking platform, given a sorted list of professional IDs where professionals with shared career interests appear in pairs, write a function to identify the one professional with a unique specialization. The professional IDs are pre-sorted, and all professionals except one have found their career interest match within the 50-mile radius.
    

    """
def search(arr):
    """
    In a professional networking platform, given a sorted list of professional IDs where professionals with shared career interests appear in pairs, write a function to identify the one professional with a unique specialization. The professional IDs are pre-sorted, and all professionals except one have found their career interest match within the 50-mile radius.
    

    """
    n = len(arr)
    XOR = 0
    for i in range(n):
        XOR = XOR ^ arr[i]
    return XOR