#include <bits/stdc++.h>
using namespace std;
int main() {
ios::sync_with_stdio(false);
cin.tie(0);
int n;
cin >> n;
vector<int> x(n);
vector<int> y(n);
for (int i = 0; i < n; i++) {
cin >> x[i] >> y[i];
}
vector<int> xs;
vector<int> ys;
for (int i = 0; i < n; i++) {
xs.push_back(x[i]);
ys.push_back(y[i]);
}
sort(xs.begin(), xs.end());
sort(ys.begin(), ys.end());
xs.erase(unique(xs.begin(), xs.end()), xs.end());
ys.erase(unique(ys.begin(), ys.end()), ys.end());
for (int i = 0; i < n; i++) {
x[i] = (int) (lower_bound(xs.begin(), xs.end(), x[i]) - xs.begin());
y[i] = (int) (lower_bound(ys.begin(), ys.end(), y[i]) - ys.begin());
}
{
vector<int> order(n);
iota(order.begin(), order.end(), 0);
sort(order.begin(), order.end(), [&](int i, int j) {
return x[i] < x[j];
});
vector<int> new_x(n);
vector<int> new_y(n);
for (int i = 0; i < n; i++) {
new_x[i] = x[order[i]];
new_y[i] = y[order[i]];
}
x = new_x;
y = new_y;
}
vector<int> fenw(n + 1);
auto Modify = [&](int p, int v) {
for (p++; p <= n; p += p & -p) {
fenw[p] += v;
}
};
auto Query = [&](int p) {
int res = 0;
for (p++; p; p -= p & -p) {
res += fenw[p];
}
return res;
};
long long ans = 0;
function<void(int, int)> Solve = [&](int L, int R) {
if (L >= R) {
return;
}
int mid = L + R >> 1;
vector<array<int, 4>> ev;
set<int> st;
for (int i = mid; i >= L; i--) {
auto it = st.lower_bound(y[i]);
if (it == st.end()) {
ev.push_back({y[i], n - 1, 1, i});
} else {
ev.push_back({y[i], *it - 1, 1, i});
}
st.insert(y[i]);
}
st.clear();
for (int i = mid + 1; i <= R; i++) {
auto it = st.lower_bound(y[i]);
if (it == st.begin()) {
ev.push_back({0, y[i], 0, i});
} else {
ev.push_back({*prev(it) + 1, y[i], 0, i});
}
st.insert(y[i]);
}
sort(ev.begin(), ev.end());
for (auto& p : ev) {
if (p[2] == 0) {
Modify(p[1], +1);
} else {
ans += Query(p[1]) - Query(p[0] - 1);
}
}
for (auto& p : ev) {
if (p[2] == 0) {
Modify(p[1], -1);
}
}
Solve(L, mid);
Solve(mid + 1, R);
};
Solve(0, n - 1);
cout << ans << '\n';
return 0;
}
