import sys
input = sys.stdin.readline

n = int(input())
F = [1]*50
for i in range(2, n+1):
    F[i] = F[i-1] + F[i-2]

print(F[n]) import sys sys input = sys.stdin.readline input sys.stdin.readline sys.stdin sys stdin readline n = int(input()) n int(input()) int input() input F = [1]*50 F [1]*50 [1] 1 50 for i in range(2, n+1):
    F[i] = F[i-1] + F[i-2] i range(2, n+1) range 2 n+1 n 1 F[i] = F[i-1] + F[i-2] F[i] F i F[i-1] + F[i-2] F[i-1] F i-1 i 1 F[i-2] F i-2 i 2 print(F[n]) print F[n] F n n = int(input()) int(input()) n input = sys.stdin.readline sys.stdin.readline input F = [1]*50 [1]*50 F
import sys
input = sys.stdin.readline

n = int(input())
F = [1]*50
for i in range(2, n+1):
    F[i] = F[i-1] + F[i-2]

print(F[n])
