Tasks are here: https://ioi2023.hu/tasks/
You can solve all IOI 2023 Day 1 tasks here: https://oj.uz/problems/source/644
In case you want to solve it in 5 hours, you can try our unofficial mirror here: https://oj.uz/contest/view/IOI2023DAY1
Currently the translations of the tasks are not provided, but we will upload it after it's available.
Also awailiable on https://ioi.contest.codeforces.com/group/32KGsXgiKA/contest/104548