#include <cstdio>
#include <cassert>
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <iostream>
#include <algorithm>
#include <vector>
#include <map>
#include <set>
#include <climits>
#include <cctype>
#include <utility>
#include <queue>
#include <cmath>
#include <complex>
#include <bitset>

using namespace std;

typedef long long LL;
typedef pair<int, int> PII;
typedef vector<int> VI;
typedef vector<PII> VPII;
typedef pair<LL, LL> PLL;
typedef pair<int, LL> PIL;
typedef pair<LL, int> PLI;
typedef double DB;

#define pb push_back
#define mset(a, b) memset(a, b, sizeof a)
#define all(x) (x).begin(), (x).end()
#define bit(x) (1 << (x))
#define bitl(x) (1LL << (x))
#define sqr(x) ((x) * (x))
#define sz(x) ((int)(x.size()))
#define cnti(x) (__builtin_popcount(x))
#define cntl(x) (__builtin_popcountll(x))
#define clzi(x) (__builtin_clz(x))
#define clzl(x) (__builtin_clzll(x))
#define ctzi(x) (__builtin_ctz(x))
#define ctzl(x) (__builtin_ctzll(x))

#define X first
#define Y second

#define Error(x) cout << #x << " = " << x << endl

template <typename T, typename U> 
inline void chkmax(T& x, U y) {
    if (x < y) x = y;
}

template <typename T, typename U>
inline void chkmin(T& x, U y) {
    if (y < x) x = y;
}

const int MN = 205;

struct BG {
    int a[100], n;
    void init() {
        memset(a, 0, sizeof a);
        n = 1;
    }
    void output() {
        for (int i = n - 1; i >= 0; i--) printf("%d", a[i]);
        puts("");
    }
} f[MN];

BG add(BG A, BG B) {
    BG C;
    C.init();
    C.n = max(A.n, B.n) + 2;
    for (int i = 0; i < C.n; i++) {
        C.a[i] = A.a[i] + B.a[i];    
    }
    for (int i = 0; i < C.n - 1; i++) {
        C.a[i + 1] += C.a[i] / 10;
        C.a[i] %= 10;
    }
    while (C.a[C.n - 1] == 0 && C.n > 1) C.n--;
    return C;
}

int main() {
    
    f[1].init();
    f[1].a[0] = 1;
    f[2].init();
    f[2].a[0] = 2;
    for (int i = 3; i < MN; i++) {
        f[i] = add(f[i - 1], f[i - 2]);
    }
    int n;
    while (scanf("%d", &n) == 1) {
        f[n].output();
    }

    return 0;
}