title: Trying to use output of a layer as an input to another layer.(KERAS tensorflow backend)
body: <p>I using Keras with Python 3. 
  I am trying to apply the network shown in the attachment<a href="https://i.stack.imgur.com/Q1pcL.jpg" rel="nofollow noreferrer">model</a>. The sequential model does not help me because the order of my model is shuffled. For example, the output of X1 is used into Y1 and X2. My code looks </p>
  
  <pre class="lang-py prettyprint-override"><code>conv1= (Convolution3D(32, 3, 3, 3, activation='relu', 
  border_mode='same', name='conv1',
  input_shape=(patch_size, img_rows, img_cols,3)))
  
  input_1=conv1.output
  
  lstm1=(ConvLSTM2D(filters=3, kernel_size=(3, 3),
  padding='same', return_sequences=True))(input_1)
  
  conv2= (Convolution3D(32, 3, 3, 3, activation='relu', 
  border_mode='same', name='conv1'))(input_1)
  
  input_2= conv2.output
  
  lstm2=(ConvLSTM2D(filters=3, kernel_size=(3, 3),
  padding='same', return_sequences=True))(input_2)
  
  conv3= (Convolution3D(32, 3, 3, 3, activation='relu', 
  border_mode='same', name='conv1'))(input_2)
  
  input_3= conv3.output
  
  lstm3=(ConvLSTM2D(filters=3, kernel_size=(3, 3),
  padding='same', return_sequences=True))(input_3)
  </code></pre>
  
  <p>then I will merge the LSTM together.
  I am getting many errors such as 'Layer conv1 has no inbound nodes'.
  Thanks in advance for you help.</p>