n=in(input())
if n == 0
print (0)
else:
a, b = 0,01
for i in range(2, n + 1 ) :
a, b = b, a +b
print b
ИЛИ
n, m = 1, 1
n, m = 1, 1a = int(input("A = "))
n, m = 1, 1a = int(input("A = "))while m <= a:
n, m = 1, 1a = int(input("A = "))while m <= a: n, m = m, m + n
n, m = 1, 1a = int(input("A = "))while m <= a: n, m = m, m + nprint(n)