Find the largest positive integer which makes it possible to color several cells of a table red such that
- There are no two red cells satisfying: the two rows in which they are have the same number of red cells, while the two columns in which they are also have the same number of red cells;
- There are two rows with exactly red cells each.
Solution
To find the largest positive integer that allows coloring several cells of a table red such that:
1. There are no two red cells satisfying: the two rows in which they are have the same number of red cells, while the two columns in which they are also have the same number of red cells.
2. There are two rows with exactly red cells each.
We need to construct a configuration that meets these criteria.
The largest possible is . This can be achieved by arranging the red cells in the topmost two rows, ensuring that the tail consists of segments with lengths .
Thus, the largest positive integer is:
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