// #include <bits/stdc++.h>
#include <iostream>
#include <cmath>
#include <algorithm>
#include <map>
#include <unordered_map>
#include <vector>
#include <iomanip>
#include <string>
#include <queue>
#include <set>
#include <deque>
using namespace std;
#define int long long
#define endl "\n"
#define fi first
#define se second
const int M=1e9+7;
const int inf = 1e14;
const int LOG=18;
const int N=7e1+5;
int n , m , c , w , k , t=1 , q=1 , x , y , z , l , r;
void solve(){
cin >> n;
vector<int>a(n);
for (int i=0;i<n;i++){
cin >> a[i];
}
if (n<=2000){
c=0;
for (int i=0;i<n;i++){
map<int,int>d;
int cn=0;
for (int j=i;j<n;j++){
d[a[j]]++;
cn=max(cn,d[a[j]]);
if (cn>(j-i+1)/2)c++;
}
}
cout << c << endl;
return;
}
c=n*(n+1)/2;
map<int,int>d;
d[0]=1;
int c1=0,c2=0;
for (int i=0;i<n;i++){
c1+=a[i]==1;
c2+=a[i]==2;
c-=d[c1-c2];
d[c1-c2]++;
}
cout << c << endl;
}
signed main()
{
// ios::sync_with_stdio(0);//DO NOT USE IN INTERACTIVE
// cin.tie(0), cout.tie(0);//DO NOT USE IN INTERACTIVE
cout << fixed << setprecision(9);
srand(time(0));
// int t=1;
// cin >> t;
for (int _=1;_<=t;_++){
solve();
q++;
}
}
