#include <bits/stdc++.h>
    
using namespace std;
    
ifstream fin("nunta.in");
ofstream fout("nunta.out");

const int base = 1000000000;

struct BigInt {
    vector < int > digit;

    BigInt operator + (const BigInt &other) {
        BigInt ret(0);

        int carry = 0;
        for(int i = 0; i < (int)digit.size() || i < (int)other.digit.size() || carry; ++i) {
            if(i == (int)ret.digit.size()) {
                ret.digit.push_back(0);
            }
            ret.digit[i] += carry + (i < (int)other.digit.size() ? other.digit[i] : 0) + (i < (int)digit.size() ? digit[i] : 0);
            carry = (ret.digit[i] >= base);
            if(carry) {
                ret.digit[i] -= base;
            }
        }

        return ret;
    }

    BigInt(int x) {
        digit.push_back(x);
    }
};

int main() {
    int n;
    fin >> n;

    BigInt A(0), B(1), C(1);
    for(int i = 0; i < n; ++i) {
        C = A + B;
        A = B;
        B = C;
    }

    fout << C.digit.back();
    for(int i = (int)C.digit.size() - 2; i >= 0; --i) {
        for(int j = 0; j < 9 - log10(C.digit[i]) - 1; ++j) {
            fout << "0";
        }
        fout << C.digit[i];
    }
    return 0;
}