#include <stdio.h>

int main() {
    int n;
    while (scanf("%d", &n) != EOF) {
        long long a = 1, b = 1, c = 2;//输出结果用64位数字保存。
        if(n ==0) printf("1\n");
        else if(n == 1) printf("1\n");
        else if(n == 2) printf("2\n");
        else {
            n -= 2;
            long long d;
            while(n>0) {
                d = a+b+c;
                a = b;
    &nbs...