#include<stdio.h>
int n,a[500],b[500],c[500];
void fibo(){
	int k,i,t,m,max;
	a[0]=a[1]=b[0]=b[1]=c[0]=c[1]=1;
	for(k=1;k<n;k++){
		if(a[0]>b[0])
			max=a[0];
		else
			max=b[0];
		m=0;
		for(i=1;i<=max;i++){
			t=m+a[i]+b[i];
			c[i]=t%10;
			a[i]=b[i];
			b[i]=c[i];
			m=t/10;
		}
		c[0]=max;
		if(m>0){
			c[0]++;
			c[c[0]]=b[c[0]]=m;
		}
		a[0]=b[0];
		b[0]=c[0];
	}
}
int main(){
	FILE *f;
	f=fopen("nunta.in","r");
	fscanf(f,"%d",&n);
	fclose(f);
	fibo();
	f=fopen("nunta.out","w");
	for(int i=c[0];i>=1;i--)
		fprintf(f,"%d",c[i]);
	fclose(f);
	return 0;
}