#include <bits/stdc++.h>
using namespace std;

const int MAX_N = 10000;
const int bi = 3e5 + 10;

string fib[MAX_N + 5];

string add(string a, string b)
{
    int ah[bi] = {0}, bh[bi] = {0}, ch[bi] = {0}, x = 0;
    int la = a.size();
    int lb = b.size();
    int lc = max(la, lb);

    for (int i = 0; i < la; i++)
    {
        ah[i] = a[la - 1 - i] - '0';
    }
    for (int i = 0; i < lb; i++)
    {
        bh[i] = b[lb - 1 - i] - '0';
    }

    for (int i = 0; i < lc; i++)
    {
        ch[i] = ah[i] + bh[i] + x;
        x = ch[i] / 10;
        ch[i] %= 10;
    }

    if (x)
    {
        ch[lc] = x;
        lc++;
    }

    while (lc > 1 && ch[lc - 1] == 0)
    {
        lc--;
    }

    string cj = "";
    for (int i = lc - 1; i >= 0; i--)
    {
        cj += (ch[i] + '0');
    }
    return cj;
}

int main()
{
    ios::sync_with_stdio(0);
    cin.tie(0);

    fib[1] = "1";
    fib[2] = "1";
    for (int i = 3; i <= MAX_N; i++)
    {
        fib[i] = add(fib[i - 1], fib[i - 2]);
    }

    int n;
    while (cin >> n)
    {
        cout << fib[n] << endl;
    }

    return 0;
}