n = int(input())
 
precision = (n+100)//4
 
unit = 10**precision
 
def isqrt(n): #binary search between 0 and n
	lo = 0
	hi = n
	mi = 0
	while lo<hi:
		mi = (lo+hi+1)//2
		test = mi*mi
		if test > n:
			hi = mi - 1
		elif test < n:
			lo = mi
		else:
			lo = hi = mi
	return lo
 
enlarged_sqrt5 = isqrt(5*unit*unit)
 
enlarged_phi = (unit + enlarged_sqrt5)//2
 
enlarged_phi_to_n = enlarged_phi**n//unit**(n-1)
 
print((enlarged_phi_to_n+unit//2)//enlarged_sqrt5)

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

MTAwMA==

1000