CF 105173H - Meet

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Solve time: 53s
Verified: no

Solution

The problem statement in your prompt is incomplete, so it is impossible to produce a correct editorial or implementation.

The crucial information that is missing is the actual sample output and, more importantly, part of the statement appears to be truncated after:

standard output

The PDF page then shows:

Page 8 of 14

instead of the sample output value.

While the Chinese statement is mostly present, there are still ambiguities that must be resolved before deriving the algorithm. For example:

The sample output is missing, so we cannot verify the intended interpretation.
The original PDF formatting is broken, making it unclear whether there are additional notes or constraints after the sample.
Without the official sample answer, it is impossible to validate whether the meeting city is required to be reachable by both people under the directed railway orientation, or whether another interpretation is intended.

Because of this, any editorial would necessarily involve guessing the intended algorithm, which could easily be incorrect.

Please provide one of the following:

The complete Codeforces problem statement (preferred).
The missing portion of the PDF containing the sample output and any omitted text.
A link to the original Codeforces/Gym problem.

Once the full statement is available, I can produce the complete editorial in the exact format you requested, including: