#include <cstdio>
#include <cstring>
#include <iostream>
#include <algorithm>
#include <vector>
#include <stack>
#include <cmath>
#include <queue>
#include <set>
#include <map>
using namespace std;
#define ll long long
#define FOR(i,j,k) for(int i =j; i<=k ;i++)
#define ll long long
#define pii pair<int,int>
const int maxn = 1000010;
const ll mod = 1e9+7;
int a[210][110];
int main()
{
    int n;
    memset(a, 0, sizeof(a));
    a[1][1] = 1,a[2][1] = 2;
    FOR(i, 3, 200){
        int jin = 0;
        FOR( j, 1, 100){
            a[i][j] = a[i-1][j] + a[i-2][j] + jin;
            jin =  a[i][j]/ 10;
            a[i][j] = a[i][j] % 10;
        }
    }

    while(~scanf("%d" ,&n))
    {
        int i;
        for(i = 100 ;i>=1;i--)
            if(a[n][i] != 0)
                break;
        for(;i>=1;i--)
            printf("%d",a[n][i]);
        printf("\n");
    }
    return 0;
}