import sys
import math

def extgcd(a:int, b:int) -> tuple[int,int,int]:
    if b==0:
        return a,1,0
    g,x1,y1=extgcd(b, a%b)
    x=y1
    y=x1-(a//b)*y1
    return g,x,y

def main():
    data = sys.stdin.read().split()
    if len(data)<2:
        return
    n,b=map(int, data[:2])

    if math.gcd(n, b)!=1:
        print("NaN")
        return

    g,x,y=extgcd(n,b)
    x%=b
    print(x)

if __name__ == "__main__":
    main()