#include <cstdio>

unsigned long long f1, f2, f3;
int n, i;

int main() {
    freopen("nunta.in","r",stdin);
    freopen("nunta.out","w",stdout);
    scanf("%d", &n); f1 = 1, f2 = 2; if (n < 3) {printf("%d", (n==1?f1:f2));return 0;}
    for (i = 3; i <= n; i++) f3 = f1+f2, f1 = f2, f2 = f3;
    printf("%d", f3);
    printf("\n%u",(1LL<<32));
}