ValueError: Input 0 of layer sequential_2 is incompatible with the layer

Значится, заделал я нейросеть, чтобы распознавать 4 символа:Греческие альфа и бета и плюс с минусом. А она мне вот такую вот выдает ошибку. ValueError: Input 0 of layer sequential_2 is incompatible with the layer: expected axis -1 of input shape to have value 4800 but received input with shape [None, 4800, 4, 4] Вот код https://colab.research.google.com/drive/1QrVGPx1ZxmpBURUatlEiEAD88yfVhO2x?usp=sharing Вот кусок

trainY = to_categorical(trainY, 4)
trainX = to_categorical(trainX, 4)
testY = to_categorical(testY, 4)
testX = to_categorical(testX, 4)
#input_shape=[1,0,0]
EPOCHS = 70
#checkpointer = ModelCheckpoint(filepath='/content/drive/MyDrive/handwritten_nums_train/point.h5', verbose=1, save_best_only=True)
H = model.fit(trainX, trainY, validation_data=(testX, testY), epochs=EPOCHS, batch_size=32)
#model.fit(trainX, trainY, batch_size=128, epochs=20, verbose=0, validation_data=(testX, testY), callbacks=[checkpointer])
print('Model trained')