Problem 43650. Church Encoding

Church encoded numeral is a function which takes two arguments f and x and applies f to x several times.

For example, if c is a church numeral 3, then the following holds. c(f,x) = f(f(f(x)))

Write a function named church(n). Input n is an nonnegative integer. Output is the church encoded numeral of n.

https://en.wikipedia.org/wiki/Church_encoding