#include<iostream>
using namespace std;

int main(){
    int limit;
    cin>>limit;
    if (limit<0){
        cout<<"Invalid input";
        return 0;
    }
    int a=0, b=1;
     
     while (a<=limit){
         cout<<a<<"";
         int next=a+b;
         b= next;
     }
     return 0;
}