#include<stdio.h>
#include<string.h>
int n;
int v0[300];
int v1[300];
int v2[300];

void adunare()
{
	int i,t=0,lim;
	lim=v1[0];
	for(i=1;i<=lim || t;i++)
	{
		t=t+v1[i]+v0[i];
		v2[i]=t%10;
		t=t/10;
	}
	v2[0]=i-1;
	memcpy(v0,v1,sizeof(v1));
	memcpy(v1,v2,sizeof(v2));
}

int main()
{
	freopen("nunta.in","r",stdin);
	freopen("nunta.out","w",stdout);
	scanf("%d",&n);
	v0[++v0[0]]=0;
	v1[++v1[0]]=1;
	for(n=n;n>=1;n--)
	{
		adunare();
	}
	int i;
	for(i=v2[0];i>=1;i--)
		printf("%d",v2[i]);
	return 0;
}