
    Design a data cleaning function for the student tracking system that processes encoded student identifiers by removing all odd-positioned characters, which represent system noise and delimiters, to extract the pure attendance and engagement metrics for dropout risk analysis. The function must maintain the sequential order of the remaining characters while eliminating all characters at odd positions in the input string.
    

    
def remove_odd(str1):
    """
    Design a data cleaning function for the student tracking system that processes encoded student identifiers by removing all odd-positioned characters, which represent system noise and delimiters, to extract the pure attendance and engagement metrics for dropout risk analysis. The function must maintain the sequential order of the remaining characters while eliminating all characters at odd positions in the input string.
    

    """
def remove_odd(str1):
    """
    Design a data cleaning function for the student tracking system that processes encoded student identifiers by removing all odd-positioned characters, which represent system noise and delimiters, to extract the pure attendance and engagement metrics for dropout risk analysis. The function must maintain the sequential order of the remaining characters while eliminating all characters at odd positions in the input string.
    

    """
    str2 = ''
    for i in range(1, len(str1) + 1):
        if i % 2 == 0:
            str2 = str2 + str1[i - 1]
    return str2