Unit 23.5

a = [[10, 20, 30, 40], [50, 60, 70, 80], [90, 100, 110, 120]]

i = 0
while i < len(a):
    j = 0
    while j < len(a[j]):                
        print(a[i][j], end=' ')
        j += 1
    print()
    i+= 1