#include <fstream>

using namespace std;

ifstream cin("nunta.in");

ofstream cout("nunta.out");

short int v[1001][300];
void te_papa_canii(int n)
{
    v[1][0]=v[2][0]=1;
    v[1][1]=v[2][1]=1;
    for (int i=3; i<=n+1; i++)
    {
        v[i][0]=v[i-1][0];
        for(int j=1;j<=v[i][0];j++)
        {
            v[i][j]+=v[i-1][j]+v[i-2][j];
            v[i][j+1]+=v[i][j]/10;
            v[i][j]%=10;
        }
        if(v[i][v[i][0]+1]!=0)
            v[i][0]++;
    }
}
int main()
{
    int n;
    cin >> n;
    te_papa_canii(n);
    for(int i=v[n+1][0];i>=1;i--)
        cout<<v[n+1][i];
    return 0;
}