#include<cstdio>
using namespace std;

short a[3][209];
short n,i,j,size,p;
int main()
{
freopen("nunta.in", "r", stdin);
freopen("nunta.out", "w", stdout); 
scanf("%d", &n);   
a[0][0]=1; 
a[1][0]=1; 
size=0;
if(n<=2)
 {printf("%d", n);
		return 0;} 
for(i=2; i<=n; i++)
  {for(j=0; j<=size; j++)
   {

    if((a[0][j]+a[1][j]+p)<10)
    {a[2][j]=a[0][j]+a[1][j]+p;
    p=0;}
    else
    {a[2][j]=(a[0][j]+a[1][j]+p)%10; 
     p=1;}
     }
  
 if(p==1)
   {size++;  a[2][size]=1;  a[1][size]=0;  p=0;}
 for(j=0; j<=size; j++)
   {a[0][j]=a[1][j];
   a[1][j]=a[2][j];}      

}
for(j=size; j>=0; j--)
printf("%d", a[2][j]);  

return 0;}