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#include <bits/stdc++.h>

using namespace std;
#define ll long long
#define maxn 510
#define maxa 30
#define maxv 20010
#define result_t pair<bool, pair<int,char>>
#define cd complex<double>

const double PI = acos(-1);


int tab[maxn];


void fft(vector<cd> &a, bool invert) {
    int n = a.size();

    for (int i = 1, j = 0; i < n; i++) {
        int bit = n >> 1;
        for (; j & bit; bit >>= 1)
            j ^= bit;
        j ^= bit;

        if (i < j)
            swap(a[i], a[j]);
    }

    for (int len = 2; len <= n; len <<= 1) {
        double ang = 2 * PI / len * (invert ? -1 : 1);
        cd wlen(cos(ang), sin(ang));
        for (int i = 0; i < n; i += len) {
            cd w(1);
            for (int j = 0; j < len / 2; j++) {
                cd u = a[i+j], v = a[i+j+len/2] * w;
                a[i+j] = u + v;
                a[i+j+len/2] = u - v;
                w *= wlen;
            }
        }
    }

    if (invert) {
        for (cd & x : a)
            x /= n;
    }
}

vector<cd> multiply(vector<int> &a) {
    int n = 1;
    while (n < 2 * (int)a.size()) {
        n <<= 1;
    }
    vector<cd> fa;
    fa.reserve(n);
    copy(a.begin(), a.end(), back_inserter(fa));
    // while((int)fa.size() != n) {
    //     fa.push_back(0);
    // }
    // fa.assign(a.begin(), a.end());
    //cout << fa.size() << endl;
    //cout << n << endl;
    fa.resize(n);
     

    fft(fa, false);
    //exit(0);

    for (int i = 0; i < n; i++) {
        fa[i] *= fa[i];
    }
    
    
    fft(fa, true);
  
    

    // vector<ll> result(n);
    // for (int i = 0; i < n; ++i) {
    //     result[i] = round(fa[i].real());
    // }
    return fa;
}

void dec (vector<cd> &x, vector<int> &y) {
    for (int i = 0; i < (int)y.size(); ++i) {
        x[2*i] -= y[i];
    }
}


int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    int n;
    cin >> n;
    for (int i = 1; i <= n; ++i) {
        cin >> tab[i];
        tab[i] += tab[i-1];
    }

    int offset = 0, maxi=0;
    for (int i = 0; i < n; ++i) {
        for (int j = i + 1; j <= n; ++j) {
            offset = min(offset, tab[j]-tab[i]);
            maxi = max(maxi, tab[j]-tab[i]);
        }
    }
    
    offset *= -1;
    int offset_3 = 3 * offset;
    vector<int> one(offset + maxi + 3);
    
    for (int i = 0; i < n; ++i) {
        for (int j = i + 1; j <= n; ++j) {
            int sum = tab[j]-tab[i] + offset;
            one[sum]++;
            //one1[sum]++;
        }
    }
    auto two = multiply(one);
    dec(two, one);
    ll res = 0;
   
    for (int i = 0; i < (int)one.size(); ++i) {
        if (one[i] == 0) {
            continue;
        }
        int oposite = -i + offset_3;
        if (oposite < (int)two.size() && oposite >= 0) {
            res += (ll)one[i] * round(two[oposite].real()) / 2;
        
            int oposite_2 = -2 * i + offset_3;
            if (oposite_2 < (int)one.size() && oposite_2 >= 0) {
                if (oposite_2 != i) {
                    res -= (ll)one[i] * (ll)one[oposite_2];
                }
                else {
                    res -= (ll)one[i] * (ll)(one[i]-1);
                }
            }
        }
    }
    cout << res / 3;
}