#include<stdio.h>
int main() {
    int n;
    int a = 0,b = 1, next;
    
    scanf("%d",&n);
    
    if (n < 0) {
        printf("Invalid input");
        return;
    }
    
    printf("%d", a);
    if(n >= 1 ){
        printf("%d", b);
    }
    next = a + b;
    while (next <= n){
        printf("%d", next);
        a = b;
        b = next;
        next = a + b;
    }
    return 0;
}