def read_hollerith(string: str) -> str:
    """
    Parse a string from a hollerith format.
    Assumes the hollerith format starts at the front of the string.
    """
    i = 0
    while string[i] != "H":
        i += 1
    length = int(string[:i])
    # +1 to skip the "H"
    return string[i+1:i+1+length]