#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using P = pair<ll, ll>;
#define rep(i, a, b) for(ll i = a; i < b; ++i)
#define rrep(i, a, b) for(ll i = a; i >= b; --i)
constexpr ll inf = 4e18;
struct SetupIO {
    SetupIO() {
        ios::sync_with_stdio(0);
        cin.tie(0);
        cout << fixed << setprecision(30);
    }
} setup_io;
int main(void) {
    ll n;
    cin >> n;
    vector<ll> a(n), even, odd;
    rep(i, 0, n) {
        cin >> a[i];
        if(a[i] % 2 == 0) {
            even.push_back(a[i]);
        } else {
            odd.push_back(a[i]);
        }
    }
    sort(a.begin(), a.end());
    sort(even.begin(), even.end());
    sort(odd.begin(), odd.end());
    vector<ll> cnt_even(even.size(), 1), cnt_odd(odd.size(), 1);
    rrep(i, (int)even.size() - 2, 0) {
        if(even[i + 1] - even[i] == 2) {
            cnt_even[i] = cnt_even[i + 1] + 1;
        }
    }
    rrep(i, (int)odd.size() - 2, 0) {
        if(odd[i + 1] - odd[i] == 2) {
            cnt_odd[i] = cnt_odd[i + 1] + 1;
        }
    }
    ll ans = n;
    rep(i, 0, n - 1) {
        if(a[i + 1] - a[i] != 1) continue;
        if(a[i] % 2 == 0) {
            ll idx = lower_bound(odd.begin(), odd.end(), a[i + 1]) - odd.begin();
            ans += cnt_odd[idx];
        } else {
            ll idx = lower_bound(even.begin(), even.end(), a[i + 1]) - even.begin();
            ans += cnt_even[idx];
        }
    }
    cout << ans << '\n';
}