#include<bits/stdc++.h>
using namespace std;
#define uint128 unsigned int128
__uint128_t dp[5005];
int main(){
	dp[1]=1;
	dp[2]=2;
	for(int i=3; i<=5000; i++){
		dp[i]=dp[i-1]+dp[i-2];
	}
	int n;
	cin>>n;
	string a;
	while(dp[n]){
		int k=(int)(dp[n]%10);
		a+=(char)(k+'0');
		dp[n]/=10;
	}
	reverse(a.begin(),a.end());
	cout<<a<<endl;
	return 0;
}