def boolean(x):
    if (x in [True, 1, '1', 'true', 'True']):
        return 'true'
    if (x in [False, 0, '0', 'false', 'False']):
        return 'false'
    raise ValueError
def boolean(x):
    if (x in [True, 1, '1', 'true', 'True']):
        return 'true'
    if (x in [False, 0, '0', 'false', 'False']):
        return 'false'
    raise ValueError