Problem C: 爬楼梯

#include <cstdio>
#include <iostream>
#include <cstring>
using namespace std;
 
const long long  MOD=10007;
 
long long a[30];
 
void init(){
    a[0]=0;
    a[1]=1;
    a[2]=2;
    a[3]=4;
    for(int i=4;i<30;i++)
        a[i]=a[i-1]+a[i-2]+a[i-3];
}
 
 
int main(){
    int T;
    scanf("%d",&T);
    init();
    while(T--){
        long long ans=1;
        int n;
        scanf("%d",&n);
        for(int i=1;i<n;i++){
            int tmp;
            scanf("%d",&tmp);
            ans*=a[tmp];
            ans%=MOD;
        }
        cout<<ans<<endl;
    }
    return 0;
}
 
/**************************************************************
    Problem: 1226
    User: MKF
    Language: C++
    Result: Accepted
    Time:0 ms
    Memory:1696 kb
****************************************************************/