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

int main()
{
    int T;
    cin >> T;
    while (T--)
    {
        int n;
        cin >> n;
        vector<pair<int, int>> sss(n);
        for (int i = 0; i < n; ++i)
        {
            int l, r;
            cin >> l >> r;
            sss[i] = {r, l};
        }

        sort(sss.begin(), sss.end());

        int count = 0;
        int last_placed = -1;
        for (const auto& seg : sss)
        {
            int r = seg.first;
            int l = seg.second;
            if (l > last_placed)
            {
                ++count;
                last_placed = r;
            }
        }

        cout << count << endl;
    }
    return 0;
}