#include <cstdio>
#include <cstring>
#include <algorithm>
#include <iostream>
#include <ctime>
#include <cmath>
using namespace std;
int n;
struct yqh
{
  int size;
  int num[1020];
  void print()
  {
    for(int i=size;i>0;--i)
    {
      printf("%d",num[i]);
    }
    printf("\n");
  }
}a[202];
int main()
{
  a[1].size=a[2].size=1;
  a[1].num[1]=1;
  a[2].num[1]=2;
  for(int i=3;i<=200;++i)
  {
    a[i].size = a[i-1].size;
    for(int j=1;j<=a[i].size;++j)
    {
      a[i].num[j]+=a[i-1].num[j]+a[i-2].num[j];
      a[i].num[j+1]=a[i].num[j]/10;
      a[i].num[j]%=10;
    }
    if(a[i].num[a[i].size+1])++a[i].size;
  }

  while(scanf("%d",&n)!=EOF)
  {
    a[n].print();
  }

  return 0;
}