open System
let rec f n k =
match k with
|_ when (k < 0) || (k > n) -> 0
| z -> 100
|_ -> ((f n (k+1)) + 1)
let x = f 10 5
printfn "%d" x
b3BlbiBTeXN0ZW0KCmxldCByZWMgZiBuIGsgPQogIG1hdGNoIGsgd2l0aAogICB8XyB3aGVuIChrIDwgMCkgfHwgKGsgPiBuKSAtPiAwCiAgIHwgeiAtPiAxMDAKICAgfF8gLT4gKChmIG4gKGsrMSkpICsgMSkKICAgCmxldCB4ID0gZiAxMCA1CgpwcmludGZuICIlZCIgeAoK