n = int(input())
if n < 2:
    print(1)
else:
    a, b = 1, 1
    for k in range(n - 1):
        a, b = b, a + b
    print(b)
 n = int(input()) n int(input()) int input() input if n < 2:
    print(1)
else:
    a, b = 1, 1
    for k in range(n - 1):
        a, b = b, a + b
    print(b) n < 2 n 2 print(1) print 1 a, b = 1, 1 a 1 b 1 for k in range(n - 1):
        a, b = b, a + b
     k range(n - 1) range n - 1 n 1 a, b = b, a + b a b b a + b a b print(b) print b n = int(input()) int(input()) n a, b = 1, 1 1 a b = 1, 1 1 b b = b, a + b a + b b a, b = b, a + b b a
n = int(input())
if n < 2:
    print(1)
else:
    a, b = 1, 1
    for k in range(n - 1):
        a, b = b, a + b
    print(b)

