from sys import stdin
def main():
    #入力
    readline=stdin.readline
    n=int(readline())
    dp=[0]*(n+1)
    for i in range(n+1):
        if i==0 or i==1:
            dp[i]=1
        else:
            dp[i]=dp[i-1]+dp[i-2]

    print(dp[n])
    
if __name__=="__main__":
    main() from sys import stdin def main():
    #入力
    readline=stdin.readline
    n=int(readline())
    dp=[0]*(n+1)
    for i in range(n+1):
        if i==0 or i==1:
            dp[i]=1
        else:
            dp[i]=dp[i-1]+dp[i-2]

    print(dp[n])
     main readline=stdin.readline readline stdin.readline stdin readline n=int(readline()) n int(readline()) int readline() readline dp=[0]*(n+1) dp [0]*(n+1) [0] 0 n+1 n 1 for i in range(n+1):
        if i==0 or i==1:
            dp[i]=1
        else:
            dp[i]=dp[i-1]+dp[i-2]

     i range(n+1) range n+1 n 1 if i==0 or i==1:
            dp[i]=1
        else:
            dp[i]=dp[i-1]+dp[i-2]

     i==0 or i==1 i==0 i 0 i==1 i 1 dp[i]=1 dp[i] dp i 1 dp[i]=dp[i-1]+dp[i-2] dp[i] dp i dp[i-1]+dp[i-2] dp[i-1] dp i-1 i 1 dp[i-2] dp i-2 i 2 print(dp[n]) print dp[n] dp n if __name__=="__main__":
    main() __name__=="__main__" __name__ "__main__" main() main def main():
    #入力
    readline=stdin.readline
    n=int(readline())
    dp=[0]*(n+1)
    for i in range(n+1):
        if i==0 or i==1:
            dp[i]=1
        else:
            dp[i]=dp[i-1]+dp[i-2]

    print(dp[n])
     def main():
    #入力
    readline=stdin.readline
    n=int(readline())
    dp=[0]*(n+1)
    for i in range(n+1):
        if i==0 or i==1:
            dp[i]=1
        else:
            dp[i]=dp[i-1]+dp[i-2]

    print(dp[n])
     main
from sys import stdin
def main():
    #入力
    readline=stdin.readline
    n=int(readline())
    dp=[0]*(n+1)
    for i in range(n+1):
        if i==0 or i==1:
            dp[i]=1
        else:
            dp[i]=dp[i-1]+dp[i-2]

    print(dp[n])
    
if __name__=="__main__":
    main()
