<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def repeat_op(repetitions, inputs, op, *args, **kwargs):
 """Build a sequential Tower starting from inputs by using an op repeatedly. It creates new scopes for each operation by increasing the counter. Example: given repeat_op(3, _, ops.conv2d, 64, [3, 3], scope='conv1') it will repeat the given op under the following variable_scopes: conv1/Conv conv1/Conv_1 conv1/Conv_2 Args: repetitions: number or repetitions. inputs: a tensor of size [batch_size, height, width, channels]. op: an operation. *args: args for the op. **kwargs: kwargs for the op. Returns: a tensor result of applying the operation op, num times. Raises: ValueError: if the op is unknown or wrong. """

  scope = kwargs.pop('scope', None)
  with tf.variable_scope(scope, 'RepeatOp', [inputs]):
    tower = inputs
    for _ in range(repetitions):
      tower = op(tower, *args, **kwargs)
    return tower