N=int(input())
B=1220703125
if N == 0:
	print(0)
	exit(0)
elif N < 0:N+=B
E=int(input())
V=0
while N%5==0:
	N//=5
	V+=1
if V>=E:
	print(0)
	exit(0)
elif V%2==1:
	print("NaN")
	exit(0)
R=N%5
if R==2 or R==3:
	print("NaN")
	exit(0)
V//=2
Q=pow(5,E-V)
i=[0]*18
for n in range(18):i[n]=pow(n if n%5!=0 else n//5,4*B//5-1,B)
N=(N*i[R]-1)%Q
r=u=p=f=q=1
for d in range(1,18):
	u*=N
	u%=Q
	p*=i[2]+1-d
	p%=Q
	f*=i[d]
	f%=Q
	if d%5==0:q*=5
	r+=p*f*u//q
	r%=Q
if R!=1:r*=2
r*=pow(5,V)
r%=Q
b=1<<29
if r<=b:
	print(r)
	exit(0)
r=Q*pow(5,V)-r
if r<=b:
	print(r)
	exit(0)
print("NaN")