#include<iostream>
#include<fstream>

using namespace std;

const int MAXN = 5005;
const long long mod = 1e9 + 7;

int n;
long long a[MAXN];

long long prefix[MAXN];

long long memo[MAXN][MAXN];
bool calculated[MAXN][MAXN];

long long calcPrefix(int l, int r)
{
    if(l==0) return prefix[r];
    return prefix[r] - prefix[l-1];
}

long long calcState(int index, int lastLength)
{
    if(index==n) return 1;
    if(calculated[index][lastLength]==true)
        return memo[index][lastLength];

    long long answer = 0;
    for(int i = index;i<n;i++)
    {
        if(calcPrefix(index-lastLength, index-1)<=calcPrefix(index, i))
            answer = ( answer + calcState(i+1, i-index+1) )%mod;
    }

    memo[index][lastLength] = answer;
    calculated[index][lastLength] = true;

    return answer;
}

int main()
{
    ifstream cin("candies.in");
    ofstream cout("candies.out");

    long long answer = 0;

    cin >> n;
    for(int i = 0;i<n;i++)
    {
        cin >> a[i];
    }

    prefix[0] = a[0];
    for(int i = 1;i<n;i++)
        prefix[i] = prefix[i-1] + a[i];

    for(int i = 0;i<n;i++)
    {
        answer = (answer + calcState(i+1, i+1))%mod;
    }

    cout << answer << '\n';
}