Update: The contest has been rescheduled to avoid the conflicts with Codeforces Round 1075 (Div 2). The contest will be held on Saturday, 24th January, 2026 at 10am (UTC+06).

Hello all,

We are thrilled to announce that the ACM ICPC Asia Dhaka Regional 2025 — Online Preliminary Replay Contest will be held on Friday, 23rd January, 2026 at 18:00 (UTC+06).

You are cordially invited to participate in the contest and we highly encourage participation in teams.

The editorial will be available shortly after the contest finishes.

We wish you all the best and hope to see you at the contest!

Hello all,

We are thrilled to announce that the ACM ICPC Asia Dhaka Regional Onsite 2025 — Replay Contest will be held on Monday, 22nd December, 2025 at 6:00PM (UTC+06).

You are cordially invited to participate in the contest and we highly encourage participation in teams.

The editorial will be available shortly after the contest finishes.

We wish you all the best and hope to see you at the contest!

How to solve this problem? I tried a lot of ideas. I used here: 1. Segment tree in every node of segment tree (Gives MLE) 2. Segment Tree in every node of BIT (gives MLE) 3. Avl tree in every node of segment tree (gives TLE) 4. Splay tree in every node of segment tree (gives TLE)

Please, help needed. :( I want to solve this prpblem

Can this problem be solved using Suffix Automaton? I want to know if we can solve this using this algorithm. Can anyone please share any ideas? Thanks in advance :)

This Solution got AC, but it gave wrong output for the input below:

3 1
a
b
c
aaaaa

The program gave output: YES but I think the output should be: NO

Am I right? If I'm, then the data set may b too weak! :(