#include<bits/stdc++.h>
#define f first
#define s second
#define int long long
#define pii pair<int,int>
using namespace std;
const int N = 4e5 + 5, mod = 1e9 + 7; // !
int D[N], U[N], t[N];
pair<int,int> e[N];
int ans = 0;
vector<int> x;
void upd(int id, int v) {
id = max(id, 1ll);
for(id; id <= (int)x.size(); id += id & (-id)) t[id] += v;
}
int get(int id) {
int ans = 0;
for(id; id >= 1; id -= id & (-id)) ans += t[id];
return ans;
}
//vector<pair<int,int>> x;
void solve(int l, int r) {
if(l == r) return;
int mid = (l + r) / 2;
vector<pair<int,int>> X, Y;
set<int> s; s.insert(0);
for(int i = mid + 1; i <= r; i++) {
D[i] = *--s.upper_bound(e[i].s);
X.push_back({e[i].s, D[i]}); // e[i].s ---- D[i] chatvlit ramdeni iseti tipiiiaaaa rom U[j] >= e[i].s DAAA e[j].s <= e[i].s && e[j].s >= D[u]
s.insert(e[i].s);
// sadamde awyobs chasvla
}
s.clear(); s.insert((int)x.size() + 1);
for(int i = mid; i >= l; i--) {
U[i] = *s.upper_bound(e[i].s);
s.insert(e[i].s);
Y.push_back({U[i], e[i].s});
}
sort(X.rbegin(), X.rend());
sort(Y.begin(), Y.end());
vector<int> roll;
for(int i = 0; i < (int)X.size(); i++) {
while(Y.size() && Y.back().f >= X[i].f) {
roll.push_back(Y.back().s);
upd(Y.back().s, 1);
Y.pop_back();
}
ans += get(X[i].f) - get(X[i].s - 1);
}
while(roll.size()) upd(roll.back(), -1), roll.pop_back();
// cout << ans;
// exit(0);
solve(l, mid); solve(mid + 1, r);
}
int GET(int b) {
return (lower_bound(x.begin(), x.end(), b) - x.begin()) + 1;
}
main(){
int n;
cin >> n;
for(int i = 1; i <= n; i++) {
cin >> e[i].f >> e[i].s;
x.push_back(e[i].f);
x.push_back(e[i].s);
}
sort(x.begin(), x.end());
x.erase(unique(x.begin(), x.end()), x.end());
for(int i = 1; i <= n; i++) {
e[i].f = GET(e[i].f);
e[i].s = GET(e[i].s);
}
sort(e + 1, e + n + 1);
solve(1, n);
cout << ans;
}
