#include<stdio.h>

int main() {
    int limit;
    scanf("%d",&limit);
    
    if(limit<0){
        printf("Invalid input");
        return 0;
    }
    int a=0,b=1;
    printf("%d",a);
    if(b<=limit)b  {
        printf("%d",b);
    }
    int c=a+b;
    while(c<=limit) {
        printf("%d",c);
        a=b;
        b=c;
        c=a+b;
    }
    
    return 0;
}