#include <cstdio>
#include <cstring>
#include <iostream>
#include <algorithm>
#include <vector>
#include <string>
using namespace std;
#define FOR(i, n, m) for(int i = n; i <= m; i++)
#define REP(i, n, m) for(int i = n; i >= m; i--)
#define PB push_back
#define MP make_pair
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> PII;
const int maxn = 210;

struct BigNumber{
        int bit[maxn];
        void Init(){
            memset(bit, 0, sizeof(bit));
            }
        BigNumber operator + (const BigNumber & B) const{
            BigNumber ret;
            ret.Init();
            int tmp = 0;
            FOR(i, 0, maxn-1){
                ret.bit[i] = (bit[i] + B.bit[i] + tmp) % 10;
                tmp = (bit[i] + B.bit[i] + tmp) / 10;
                }
            return ret;
            }
        void operator = (const BigNumber & B){
            FOR(i, 0, maxn-1) bit[i] = B.bit[i];
            }
        void Print(){
            bool flag = false;
            REP(i, maxn-1, 0){
                if (flag) cout<<bit[i];
                else if(bit[i] != 0) {
                    flag = true;
                    cout<<bit[i];
                    }
                }
            if(!flag) cout<<"0";
            cout<<endl;
            }
        };
        

int main(){
        int n;
        while(cin>>n){
            if(n == 0) {
                cout<<0<<endl;
                continue;
                }
            BigNumber x, y;
            x.Init(), y.Init();
            y.bit[0] = 1;

            FOR(i, 1, n){
                BigNumber t = y;
                y = x + y;
                x = t;
                }
            y.Print();
            }
        return 0;
}