#include <fstream>
using namespace std;

int main(){
    ifstream f("nunta.in");
    ofstream g("nunta.out");
    int n;
    f >> n;

    char big[1000] = {}, small[1000] = {};
    big[0] = 1;
    for( ; n; --n){
        for(int i = 0; i < 1000; ++i){
            small[i] += big[i]; }
        for(int i = 0, carry = 0; i < 1000; ++i){
            carry += small[i];
            small[i] = carry % 10;
            carry /= 10; }
        for(int i = 0; i < 1000; ++i){
            swap(big[i], small[i]); } }
    int i = 999;
    while(!big[i]) --i;
    for( ; i >= 0; --i) g << char(big[i] + '0');
    return 0; }