# Write a NumPy program to stack arrays in sequence vertically.  
 import numpy as np    
print("\nOriginal arrays:")
x = np.arange(9).reshape(3,3)
y = x*3
print("Array-1")
print(x)
print("Array-2")
print(y)
new_array =  np.vstack((x,y))
print("\nStack arrays in sequence vertically:")
print(new_array)
