//#include <bits/stdc++.h>
#include <iostream>
#include <cstdio>
#include <cmath>
#include <cstring>
#include <algorithm>

using namespace std;

#define N 10010
#define mod 9973

struct bign {
    int len, dig[N];
    bign() {
        len = 0, dig[0] = 0;
    }
    bign(int k){
        len = 0, dig[0] = 0;
        if(k > 0){
            for(; k; k /= 10) dig[len++] = k % 10;
            len--;
        }
    }
    void output() {
        for(int i = len; i >= 0; --i)
            printf("%d", dig[i]);
    }
    bign operator + (const bign &b) const {
        int i, carry;
        bign c;
        for(i = carry = 0; i <= len || i <= b.len || carry; ++i) {
            if(i <= len) carry += dig[i];
            if(i <= b.len) carry += b.dig[i];
            c.dig[i] = carry % 10;
            carry /= 10;
        }
        c.len = i - 1;
        return c;
    }
};
bign f[240];
int main(){
    f[1] = bign(1);
    f[2] = bign(2);
    for(int i = 3; i < 205; ++i)
        f[i] = f[i-1] + f[i-2];
    int n;
    while(scanf("%d", &n) != EOF){
        f[n].output();
        puts("");
    }
    return 0;
}