Five rows of circles, five in each row, the second vacancy in the first row, how to connect them with horizontal lines and vertical lines?

The extension of the classic 7-bridge problem, because this is an even number of points, so you can't draw a stroke at all.

Now look at the schematic diagram below! I will make your photos more popular.

Oxycarbonylation

XOXOX

OXOXO

XOXOX

OXOXO

In this way, we can find that if you follow the rules, you will inevitably encounter X when you come out of O, and you will inevitably encounter O when you come out of X. But after removing the second ring (that is, X) in the first row, carefully count the number of OX in the above figure-

O- 13 X- 1 1。

That is to say, no matter how to connect, if you want to connect 24 rings, there must be two O's connected together, or duplicated, or any other illegal connection.

So there is no solution to this problem. ...