//@formatter:off #include #define rep(i,n) for (int i = 0; i < int(n); ++i) #define rrep(i,n) for (int i = int(n)-1; i >= 0; i--) #define rep2(i,s,n) for (int i = int(s); i < int(n); ++i) #define all(a) a.begin(),a.end() #define rall(a) a.rbegin(),a.rend() #define pb push_back #define eb emplace_back #define vi vector #define vvi vector> #define vl vector #define vvl vector> #define vd vector #define vvd vector> #define vs vector #define vc vector #define vvc vector> #define vb vector #define vvb vector> #define vp vector

#define vvp vector> using namespace std; using ll = long long; using P = pair; using LP = pair; template istream& operator>>(istream &is,pair &p) { return is >> p.first >> p.second; } template ostream& operator<<(ostream &os,const pair &p) { return os<<'{'< istream& operator>>(istream &is,vector &v) { for(T &t:v){is>>t;} return is; } template ostream& operator<<(ostream &os,const vector &v) { os<<'[';rep(i,v.size())os< bool chmin(T& a,T b) {if(a > b){a = b; return true;} return false;} template bool chmax(T& a,T b) {if(a < b){a = b; return true;} return false;} const int inf = 1001001001; const ll linf = 1001001001001001001; //@formatter:on int main() { ios::sync_with_stdio(false); cin.tie(nullptr); cout.tie(nullptr); int n; cin >> n; vi p(n); cin >> p; ll ans = 0; set st; st.insert(p[0]); int r = 1; rep(l, n - 1) { if (r == l + 1) { st.insert(p[r++]); } while (r < n) { st.insert(p[r]); auto it = st.begin(); int m = *it; it++; int s = *it; it = st.end(); it--; int M = *it; if(M > m+s) { st.erase(st.find(p[r])); break; } r++; } ans += r - (l + 1); st.erase(st.find(p[l])); } cout << ans << endl; }