def fibonacci(F,n):
    F[0] = 1
    F[1] = 1
    for i in range(2,n+1,1):
        F[i] = F[i-1] + F[i-2]
    return F[n]

def main():
    n = int(input())
    F  = [0]*(n+1)
    ans = fibonacci(F,n)
    return ans

print(main())
 def fibonacci(F,n):
    F[0] = 1
    F[1] = 1
    for i in range(2,n+1,1):
        F[i] = F[i-1] + F[i-2]
    return F[n] fibonacci F[0] = 1 F[0] F 0 1 F[1] = 1 F[1] F 1 1 for i in range(2,n+1,1):
        F[i] = F[i-1] + F[i-2]
     i range(2,n+1,1) range 2 n+1 n 1 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 return F[n] F[n] F n F F n n def main():
    n = int(input())
    F  = [0]*(n+1)
    ans = fibonacci(F,n)
    return ans main n = int(input()) n int(input()) int input() input F  = [0]*(n+1) F [0]*(n+1) [0] 0 n+1 n 1 ans = fibonacci(F,n) ans fibonacci(F,n) fibonacci F n return ans ans print(main()) print main() main def fibonacci(F,n):
    F[0] = 1
    F[1] = 1
    for i in range(2,n+1,1):
        F[i] = F[i-1] + F[i-2]
    return F[n] def fibonacci(F,n):
    F[0] = 1
    F[1] = 1
    for i in range(2,n+1,1):
        F[i] = F[i-1] + F[i-2]
    return F[n] fibonacci def main():
    n = int(input())
    F  = [0]*(n+1)
    ans = fibonacci(F,n)
    return ans def main():
    n = int(input())
    F  = [0]*(n+1)
    ans = fibonacci(F,n)
    return ans main
def fibonacci(F,n):
    F[0] = 1
    F[1] = 1
    for i in range(2,n+1,1):
        F[i] = F[i-1] + F[i-2]
    return F[n]

def main():
    n = int(input())
    F  = [0]*(n+1)
    ans = fibonacci(F,n)
    return ans

print(main())

