#include #include #include using namespace std; typedef long long ll; typedef vector vl; typedef vector vvl; const ll mod=1e9+7; ll n; int main(){ cin>>n; vvl dp(n+1,vl(n+1)),DP(n+1,vl(n+1)); dp[0][0]=1; DP[1][1]=1; vl a(n); for(int i=2;i