what is wrong submission but passed 306759678

this is the changed one and passed which i think is correct 309488880

ask gives hash of string from l to r

whats wrong : inv[i] gives modular inverse of factorial of i

whats correct : inv[i] should be modular inverse of power of i base prime (P)

why i think this has happened : maybe due to combined probability of binary search, unsufficient tests, and bunch of luck i manage to AC the problem XD