#include<cstdio>
#include<iostream>
#include<sstream>
#include<cstdlib>
#include<cmath>
#include<cctype>
#include<string>
#include<cstring>
#include<algorithm>
#include<stack>
#include<queue>
#include<set>
#include<map>
#include<ctime>
#include<vector>
#include<fstream>
#include<list>

using namespace std;

long long res1[91];
char res2[111][100];

void BigAdd(char *a,char *b,char *s)//a < b needReverse
{
    int i = 0;
    int d = 0;
    while(a[i] != '\0')
    {
        s[i] = a[i] + b[i] + d - 48;
        d = 0;
        if(s[i] >= 58)
        {
            s[i] -= 10;
            d = 1;
        }
        ++i;
    }
    while(b[i] != '\0')
    {
        s[i] = b[i] + d;
        d = 0;
        if(s[i] >= 58)
        {
            s[i] -= 10;
            d = 1;
        }
        ++i;
    }
    if(d == 1)
        s[i++] = 49;
    s[i] = '\0';

}

int main()
{
    //ios::sync_with_stdio(false);

    //freopen("F:\\data.txt","r",stdin);

    memset(res1,0,sizeof(res1));
    memset(res2,0,sizeof(res2));

    res1[0] = 0;
    res1[1] = 1;
    res1[2] = 2;
    res1[3] = 3;

    for(int i = 4; i <= 91; ++i)
    {
        res1[i] = res1[i-1] + res1[i-2];
    }

    sprintf(res2[0],"%I64d",res1[90]);
    sprintf(res2[1],"%I64d",res1[91]);
    reverse(res2[0],res2[0]+strlen(res2[0]));
    reverse(res2[1],res2[1]+strlen(res2[1]));

    for(int i = 2; i <= 110; ++i)
    {
        BigAdd(res2[i-2],res2[i-1],res2[i]);
    }
    for(int i = 1; i <= 110; ++i)
    {
        reverse(res2[i],res2[i]+strlen(res2[i]));
    }

    int n;
    while(scanf("%d",&n) != EOF)
    {
        if(n == 0)
            printf("\n");
        else if(n <= 90)
        {
            printf("%I64d\n",res1[n]);
        }
        else
        {
            printf("%s\n",res2[n-90]);
        }
    }


    return 0;
}