OJ Board

In this problem, substitution cipher is provided first followed by permutation cipher
For the word VICTORIOUS, applying substitution we get WJDUPSJPVT, applying permutation we get JWPUDJSTVP, this is easily understandable,
But for HEHE, applying substitution we get IFIF, applying permutation we get FIFI, am i wrong or is that something i am missing.
Scratching my head for almost 3 hours.

"Substitutes for all letters must be different. For some letters substitute letter may coincide with the original letter."
It is never said that substituetes letters will be always next ones.
Hope this input will help.
Input: Output: