An English text needs to be encrypted using the following encryption scheme.
First, the spaces are removed from the text. Let be the length of this text.
Then, characters are written into a grid, whose rows and columns have the following constraints:
For example, the sentence , after removing spaces is characters long. is between and , so it is written in the form of a grid with 7 rows and 8 columns.
If multiple grids satisfy the above conditions, choose the one with the minimum area, i.e. .
The encoded message is obtained by displaying the characters in a column, inserting a space, and then displaying the next column and inserting a space, and so on. For example, the encoded message for the above rectangle is: