Read From User Input (integer) And Reduce It By Multiplying Its Non-zero Digits

Write a program that reads from the user an integer and reduce it by multiplying its non-zero digits. The result of the multiplication is a number which is to be reduced as the initial one. This process continues until an integer of one single digit is obtained. For example:

64734502 (6 * 4 * 7 * 3 * 4 * 5 * 2) 20160 (2 * 1 * 6) 12 (1 * 2) 2

Your program should display the number obtained in every iteration.

Sample run1
Enter an integer: 64734502
After iteration 1: 20160
After iteration 2: 12
After iteration 3: 2

Sample run2
Enter an integer: 97737999
After iteration 1: 6751269
After iteration 2: 22680
After iteration 3: 192
After iteration 4: 18
After iteration 5: 8