At first step every letter is replaced with the corresponding number:a with 0, b with 1,c with 2, …, z with 25.Then 5 is added to the first number, the first number is added to the second one, the second number – to the third one and so on. After that if some number exceeds 25 it is replaced with the residue of division of this number by 26. And then those numbers are replaced back with the letters.
，仿佛一支飘荡在水上的华丽咏叹调。
