#include "bits/stdc++.h"

using namespace std;
using ll = long long;

ll numSubseq(ll n) {
    return n * (n + 1) / 2;
}

void Main() {
    ll N;
    cin >> N;
    vector<ll> A(N, 0);
    for (ll i = 0; i < N; ++i) {
        cin >> A[i];
    }

    map<ll, ll> ones;
    bool reset = true;
    ll temp = 0;
    for (ll i = 0; i < N; ++i) {
        if (A[i] == 1) {
            ++temp;
        }
        else {
            if (temp == 0) {
                continue;
            }
            if (ones.count(temp) == 0) {
                ones.emplace(temp, 0);
            }
            ones[temp] += 1;
            temp = 0LL;
        }
    }
    if (ones.count(temp) == 0) {
        ones.emplace(temp, 0);
    }
    ones[temp] += 1;

    ll ans = numSubseq(N);
    for (auto e : ones) {
        ans -= numSubseq(e.first) * e.second;
    }
    cout << ans << endl;
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    std::cout << std::fixed << std::setprecision(15);
    Main();
    return 0;
}