#include<bits/stdc++.h>
#define Mod 1000000007
using namespace std;
typedef long long ll;
void read()
{
	freopen("duel.in","r",stdin);
    freopen("duel.out","w",stdout);
}
ll i,j,p,q,n,m,k,a[306],dp[100006],s,ans,S;
int main()
{
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);
	cout.tie(NULL);
	read();
	cin>>n;
	for(i=1;i<=n;i++)
	{
		cin>>a[i];
		S+=a[i];
	}
	///0 , a[i] ili 2*a[i]
	dp[0]=1;
	for(i=1;i<=n-1;i++)
	{
		s+=2*a[i];
		//cout<<s<<endl;
		for(j=s;j>=1;j--)
		{
			if(2*a[i]<=j)
				dp[j]+=dp[j-2*a[i]];
			if(a[i]<=j)
				dp[j]+=dp[j-a[i]];	
			dp[j]%=Mod;
		}
	}
	for(i=0;i<=S;i++)
	{
		/**
		if(i%2==0)
		cout<<i/2<<" ";
		else
		cout<<i/2<<".5 ";
		cout<<dp[i]<<endl;
		*/
		q=s-i;
		//cout<<i<<"  iq  "<<q<<endl;
		///raven
		if(i+a[n]>S ||(q<=S && q+a[n]>S))
			ans+=dp[i],ans%=Mod;
		///pobeda
		if(i+2*a[n]>S && q<=S)
			ans+=dp[i],ans%=Mod;
		///zaguba
		if(i<=S && q<=S && q+2*a[n]>S)
			ans+=dp[i],ans%=Mod;
		//cout<<ans<<"  ans "<<endl;
	}
	cout<<ans<<endl;
	return 0;
}