def METHOD_NAME(format, s):
    try:
        c0 = format[s]
    except IndexError:
        c0 = None
    try:
        c1 = format[s + 1]
    except IndexError:
        c1 = None
    try:
        c2 = format[s + 2]
    except IndexError:
        c2 = None
    return (c0, c1, c2)