#include <fstream>
using namespace std;
       ifstream in("nunta.in");
       ofstream out("nunta.out");
int n, fib1,fib2;
void fibo( int n )
{
    while ( n>2 )
    {
       fib1+=fib2;
       fib2+=fib1;
       n--;
    }
}
int main()
{
    fib1=1;
    fib2=1;
     int n; in>>n;
     if( n==1 ) out<<1;
     fibo(n);
     if( n%2 ) out<<fib2; else out<<fib1;

    return 0;
}