#include <fstream>

using namespace std;
int n,i,k,m,x,t,z,y,nr;
char a[210],b[210];
ifstream fin ("nunta.in");
ofstream fout ("nunta.out");

int main (){

    fin>>n;
    // fibonacci
    //a[0] = a[1] = b[0] = b[1] = 1;

    a[1] = b[1] = 1;
    y = 1;
    for (k=1;k<n;k++){
        t = 0;
        for (i=1;i<=y;i++){
            nr = b[i];
            b[i] += a[i]+t;
            if (b[i] >= 10){
                t = 1;
                b[i] -= 10;
            }
            else
                t = 0;
            a[i] = nr;
        }
        if (t != 0)
            b[++y] = t;
        //for (i=1;i<=y;i++)
          //  a[i] = b[i];
    }
    for (i=y;i>=1;i--)
        fout<<(int)b[i];


    return 0;
}