#include <bits/stdc++.h> using namespace std; const int N = 1e6 + 005; struct Node{ int x, y; bool operator < (const Node &o) const { if (y != o.y) return y < o.y; return x < o.x; } }a[N]; int main() { int x; cin >> x; for (int adf = 1; adf <= x; adf++) { int n, ans = 0; cin >> n; for (int i = 1; i <= n; i++) cin >> a[i].x >> a[i].y; sort(a + 1, a + n + 1); for (int i = 1; i < n; i++) { ans++; if (a[i].y < a[i + 1].x) ans++; } cout << ans << endl; for (int i = 1; i <= n; i++) a[i].x = a[i].y = 0; } }