Answer:
2
Explanation:
no. 1 is 19247
no. 2 is 7429 ,so the last four number of 19247 are reply
no. 3 is 924 ,so the last three number of 7429 are reply
no. 4 is 42 ,so the last two number of 924 are reply
no. 5 is 2,so, the last number of 42 are reply