n=int(input())
a=1
b=1
if n==0 or n==1:
    print(1)
else:
    for i in range (n):
        a,b=b,a+b
    print(a) n=int(input()) n int(input()) int input() input a=1 a 1 b=1 b 1 if n==0 or n==1:
    print(1)
else:
    for i in range (n):
        a,b=b,a+b
    print(a) n==0 or n==1 n==0 n 0 n==1 n 1 print(1) print 1 for i in range (n):
        a,b=b,a+b
     i range (n) range n a,b=b,a+b a b b a+b a b print(a) print a b=b,a+b a+b b a=1 1 a b=1 1 b a,b=b,a+b b a n=int(input()) int(input()) n
n=int(input())
a=1
b=1
if n==0 or n==1:
    print(1)
else:
    for i in range (n):
        a,b=b,a+b
    print(a)
