package main

import . "fmt"

func main() {
	var n,b uint
	Scan(&n,&b)
	n %= b
	for i := uint(0); i < b+ b; i++ {
		if (n*i-1+b)%b == 0 {
			Println(i)
			return
		}
	}
	Println("NaN")
}