McCarthy is a famous theorician of computer science. In his work, he defined a recursive function,
called f91 that takes as input a positive integer N and returns a positive integer defined as follows:
If N <= 100, then f91(N) = f91(f91(N+11));
If N >= 101, then f91(N) = N-10.
Write a program, that computes McCarthy's f91.
The input tests will consist of a series of positive integers, each integer is at most 1,000,000. There
will be at most 250,000 test cases. Each number is on a line on its own. The end of the input is
reached when the number 0 is met. The number 0 shall not be considered as part of the test set.
The program shall output each result on a line by its own, following the format given in the sample
Sample Input Sample Output
f91(500) = 490
f91(91) = 91