#include <iostream>
#include <cstdio>
#include <cstring>
#include <string>
#define LL long long
using namespace std;
const int N = 222;
string dp[N];

string add(string a, string b) {
    string ret;
    int la = a.size(), lb = b.size();
    if (la > lb)
        for(int i = 0; i < la - lb; ++i)
        b = '0' + b;
    else
        for(int i = 0; i < lb - la; ++i)
            a = '0' + a;
    la = a.size();
    int t, c = 0;
    for(int i = la - 1; i >= 0; --i) {
        t = a[i] - '0' + b[i] - '0' + c;
        c = t / 10, t %= 10;
        ret = char(t + '0') + ret;
    }
    if (c) ret = char(c + '0') + ret;
    return ret;
}

int main() {
    dp[1] = "1", dp[2] = "2";
    for (int i = 3; i <= 200; ++i)
        dp[i] = add(dp[i - 1], dp[i - 2]);
    int n;
    while (~scanf("%d", &n))
        cout << dp[n] << endl;
    return 0;
}