reshape error

[ssbilakeri]

x_train, x_test, y_train, y_test = train_test_split(images, labels, test_size=0.33, shuffle= True)

model_input = Input(shape=(224,224, 3))
softmax, pre_logits = base_network()
x_train_flat = x_train.reshape(-1, 163968)

x_train_flat = x_train.reshape(-1, 163968) ValueError: cannot reshape array of size 1304626176 into shape (163968)

what is the exact reason for this. please help me