hdu 5365 /BC 50CThe mook jong

#include <iostream>
#include <cstring>
#include <string>
#include <cstdio>
#include <cmath>
#include <algorithm>
#include <vector>
#include <queue>
#include <map>
#include<set>
#include<stack>
#define bug puts("bugbugbug");
using namespace std;
typedef long long ll;
ll dp[100]={0};
ll dfs(int id)
{
    if(id<=0)return 1;
    if(dp[id])return dp[id];
     return dp[id]=dfs(id-1)+dfs(id-3);

}
int main()
{
    dfs(60);
    int n;
    while(~scanf("%d",&n))
    {
       printf("%I64d\n",dp
-1);
    }
}