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