#include <cstdio>
#include <iostream>
#include <cstring>
using namespace std;

#define MAXN 201

int arr[MAXN][MAXN];
int len[MAXN];

void init()
{
    memset (arr, 0, sizeof(arr));
    memset (len, 0, sizeof(len));
    arr[1][0] = 1, len[1] = 1;
    arr[2][0] = 2, len[2] = 1;
    for (int i = 3; i < MAXN; ++i) {
        for (int j = 0; j < len[i-1]; ++j) {
            arr[i][j] = arr[i-1][j] + arr[i-2][j];
        }
        len[i] = len[i-1];
        int jw = 0;
        for (int j = 0; j < len[i]; ++j) {
            arr[i][j] += jw;
            jw = arr[i][j]/10;
            arr[i][j] %= 10;
        }
        while (jw) {
            arr[i][len[i]++] = jw%10;
            jw /= 10;
        }
    }
}

void print(int n)
{
    for (int i = len[n]-1; i >= 0; --i){
        printf("%d", arr[n][i]);
    }
    printf("\n");
}
int main()
{
    int n;
    init();
    while (~scanf ("%d", &n)) {
        print(n);
    }
    return 0;
}