#include <bits/stdc++.h>
using namespace std;

template<typename T>
vector<pair<T,long long>> RLE(vector<T> &A){
    if(A.size() == 0) return {};
    vector<pair<T,long long>> ret;
    T back = A.at(0);
    long long streak = 1;
    for(int i=1; i<A.size(); i++){
        if(back == A.at(i)) streak++;
        else{
            ret.push_back({back,streak});
            back = A.at(i); streak = 1;
        }
    }
    ret.push_back({back,streak});
    return ret;
}
vector<pair<char,long long>> RLE(string &s){
    if(s.size() == 0) return {};
    vector<pair<char,long long>> ret;
    char back = s.at(0);
    long long streak = 1;
    for(int i=1; i<s.size(); i++){
        if(back == s.at(i)) streak++;
        else{
            ret.push_back({back,streak});
            back = s.at(i); streak = 1;
        }
    }
    ret.push_back({back,streak});
    return ret;
}

int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);

    int N; cin >> N;
    vector<int> A(N);
    for(auto &a : A) cin >> a;

    auto B = RLE(A);
    long long answer = 0;
    for(int i=0; i<B.size(); i++){
        auto [a2,l2] = B.at(i);
        answer += l2*(l2+1)/2;
        int l = i-1,r = i+1;
        while(0 <= l && r < B.size()){
            auto [a1,l1] = B.at(l);
            auto [a3,l3] = B.at(r);
            if(a1+a3 == a2+a2){
                answer += min(l1,l3);
                if(l1 != l3) break;
            }
            else break;
            l--,r++;
        }
    }
    for(int i=1; i<B.size(); i++){
        auto [a2,l2] = B.at(i-1);
        auto [a3,l3] = B.at(i);
        answer += min(l2,l3);
        if(l2 != l3) continue;
        int l = i-2,r = i+1;
        while(0 <= l && r < B.size()){
            auto [a1,l1] = B.at(l);
            auto [a4,l4] = B.at(r);
            if(a1+a4 == a2+a3){
                answer += min(l1,l4);
                if(l1 != l4) break;
            }
            else break;
            l--,r++;
        }
    }
    cout << answer << endl;
}