//GIVE ME AC!!!!!!!!!!!!!!!!!
#pragma GCC target("avx")
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
#include<bits/stdc++.h>
#define ll long long
#define floatset() fixed<<setprecision(15)
#define all(n) n.begin(),n.end()
#define rall(n) n.rbegin(),n.rend()
#define rep(i, s, n) for (ll i = s; i < (ll)(n); i++)
using namespace std;
const int dx[4] = {1, 0, -1, 0};
const int dy[4] = {0, 1, 0, -1};
const ll inf =1e18;
const ll MOD=1000000007;
const ll mod=998244353;
const double pi=acos(-1);
using P=pair<ll,ll>;
void insert(set<pair<int,int>> &st, int v) {
    auto t = st.lower_bound({v-1,2});
    if (t != st.end() && t->first == v-1) t = st.erase(t);
    else st.insert({v,1});
    if (t != st.end() && t->first == v+1) st.erase(t);
    else st.insert({v,2});
}
// mexを計算
int mex(set<pair<int,int>> &st) {
    auto t = st.lower_bound({0,-1});
    if (t->first != 0) return 0;
    else {
        t++;
        return t->first + 1;
    }
}
int main(){
  ll n;
  cin>>n;
  ll a[n];
  rep(i,0,n){
    cin>>a[i];
  }
  ll ans=0;
  rep(i,0,n){
    set<pair<int,int>>s;
    rep(j,i,n){
      insert(s,a[j]);
      ans+=mex(s);
    }
  }
  cout<<ans<<endl;
}