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Checklist VsOSh AI 2026 School Stage (Moscow), grades 9–11 · Task 6

Neural Network Training Report

Russian title: Отчёт об обучении нейросети

From the clock times (HH:MM) logged after each epoch, compute the minimum possible total training time.

  • Algorithmic programming (time arithmetic)
  • Russian original · English translation

The task

Training ran for n epochs; after each epoch Dima wrote down the current time in 24-hour HH:MM format (seconds are not recorded, so 13:03 may mean 13:03:59). Compute the minimum amount of time the training could have taken, rounded down to whole minutes.

Abridged and translated by SOTA from the official Russian materials. The official statement has the exact rules, and it wins wherever this summary differs.

In English

This task was published in Russian. SOTA translated its 4 files into English on 16 September 2026.

Read the task statement in English 418 words

Neural Network Training Report

English translation by SOTA – AI Community of the Russian original. Organisers who would like this translation removed can email [email protected].

Task 6 of the school stage (Moscow) of the All-Russian School Olympiad (VsOSh) 2025/26 in artificial intelligence, grades 9–11. Original: tasks-ai-9-11-sch-msk-25-26.pdf.

Neural network training report · standard input · standard output · 1 second · 256 megabytes

Translator's note: in the original, this line is printed run together, without labels. It gives the task title, then "standard input", "standard output", "1 second" and "256 megabytes", i.e. the input file, output file, time limit and memory limit.

Neural network training is usually divided into epochs. During one epoch of training, the model passes through the training dataset once.

Dima worked on a new project for a long time. Its training took as many as nn epochs. After each epoch, Dima wrote down the current time in the format HH:MMHH:MM (for example, 13:0313:03). Now Dima wonders what the minimum amount of time spent on training the model could have been.

Dima is very busy with work tasks at the moment, so he has turned to you for help. Compute the minimum amount of time that could have been spent on training the model.

Input format

The first line of the input contains one integer nn (2n1042 \le n \le 10^4).

The next nn lines give the moments of time at which each successive epoch ended, in the format HH:MMHH:MM (24-hour format).

Output format

Output one integer: the minimum number of minutes that could have been spent on training the model. Round the answer down to the nearest whole number of minutes.

Note

In the first test example, exactly 10 full hours passed (1424)(14 - 24). There were also 56 minutes from 13:0313:03 to 14:0014:00 (not 57, because 13:0313:03 could have been 13:03:5913:03:59). And another 15 minutes passed from 00:0000:00 to 00:1500:15. In total, 1060+56+15=67110 \cdot 60 + 56 + 15 = 671.

Translator's note: the paper does not print the test examples that this note refers to.

Translator's note: the statement paper gives only the total for the olympiad (112 points); the official solutions give this task a maximum of 20 points (1 point for each test not taken from the statement).

Translated by SOTA. The Russian original is the official version and wins wherever the two differ. Translated from the statement and solution PDFs of the Moscow school stage (grades 9–11) on vos.olimpiada.ru. The papers do not print the test examples that the note refers to, and the task's header line (title, input/output, limits) is run together in the original. If you organise this olympiad and would like the translation removed, email [email protected] and we will take it down.

At a glance

You get
Standard input: n (2 ≤ n ≤ 10⁴), then n times in HH:MM format.
You submit
One integer: the minimum number of minutes.
Scoring
Program checked on tests (per-test scoring not stated in the statement file).
Rules
  • Time limit 1 s; memory limit 256 MB.
Format
School stage (Moscow), started 24 October 2025, grades 9–11; individual; online testing system; maximum 112 points for the paper.

Details

Year
2026, Moscow, Russia (online testing system)
Round
School Stage (Moscow), grades 9–11 · Task 6
Language
Russian; English translation by SOTA
License
Not stated by the source