#include <stdio.h>

using namespace std;

FILE*f=fopen("nunta.in","r");

int main()
{
    unsigned  a=0,b=1,x=0,y=0;
    unsigned short n;
    fscanf(f,"%d",&n);
    fclose(f);
    while (n>0)
    {
        n--;
        b=a+b;
        y=x+y;
        a=b-a;
        x=y-x;
        y=b/1000000000+y;
        b=b%1000000000;

    }
    FILE*f=fopen("nunta.out","w");
    if (y>0) fprintf(f,"%u",y);
    fprintf(f,"%u",b);
    fclose(f);
    return 0;
}