#include<cstdio>

 #include<cmath>

 #include<cstring>

 #include<iostream>

 #include<algorithm>

 using namespace std;

 const double f=(sqrt(5.0)+)/2.0;

 int fi[];

 int main()

 {

     int n,i;

     double bit;

     fi[]=;fi[]=fi[]=;

     for(i=;i<=;i++)

     {

         fi[i]=fi[i-]+fi[i-];

     }

     while(scanf("%d",&n)!=EOF)

     {

         if(n<=)

             printf("%d\n",fi[n]);

         else{

             bit=-0.5*log10(5.0)+((double)n)*log(f)/log(10.0);

             bit=bit-(int)bit;

             bit=pow(10.0,bit);

             while(bit<)bit*=;

             printf("%d\n",(int)bit);

         }

     }

     return ;

 }