I am trying to solve the problem for a long time but still didn't get any idea how to solve it. It would be great if you help me to solve it. Problem Link : https://vjudge.net/contest/332542#problem/A

Since the contest is ended that's why I share the vjudge link because I think everyone has not a light oj id and this problem is from light online judge(loj). Thanks in advance :) sorry for my poor english. :)