#include <bits/stdc++.h>
#define rep(i, s, e) for (int i = s; i <= e; i++)
using namespace std;
const int N = 2e6 + 10;
int n, l[N], r[N], tr[N];
int query(int x)
{
    int ret = 0;
    for (; x; x -= x & -x)
        ret = max(ret, tr[x]);
    return ret;
}
void update(int x, int k)
{
    for (; x <= 3 * n; x += x & -x)
        tr[x] = max(tr[x], k);
}
struct node
{
    int x, y, no, ans;
    friend bool operator<(node a, node b)
    {
        if (a.x == b.x)
            return a.y < b.y;
        return a.x < b.x;
    }
};
int main()
{
    ios::sync_with_stdio(0), cin.tie(0);
    int T;
    cin >> T;
    while (T--)
    {
        cin >> n;
        rep(i, 1, 3 * n) tr[i] = 0;
        rep(i, 1, n) cin >> l[i] >> r[i];
        vector<node> v = {{1, 2 * l[1] - 2}};
        rep(i, 1, n)
        {
            if (i == 1 || r[i] > r[i - 1])
                v.push_back({i, 2 * r[i]});
            if (i == n || l[i] < l[i + 1])
                v.push_back({i + 1, 2 * l[i] - 2});
            if (i > 1 && r[i] > r[i - 1])
                v.push_back({i, 2 * r[i - 1] + 1});
        }
        sort(v.begin(), v.end(), [](node a, node b)
             { return a.y < b.y; });
        for (int l = 0, r; l < v.size(); l = r + 1)
        {
            r = l;
            while (r < v.size() && v[r].y == v[l].y)
                r++;
            r--;
            rep(i, l, r)
            {
                v[i].no = l + 1;
            }
        }
        sort(v.begin(), v.end());
        for (int l = 0, r; l < v.size(); l = r + 1)
        {
            r = l;
            while (r < v.size() && v[r].x == v[l].x)
                r++;
            r--;
            rep(i, l, r)
                v[i]
                    .ans = query(v[i].no - 1);
            rep(i, l, r)
                update(v[i].no, v[i].ans + 1);
        }
        cout << query(3 * n) << endl;
    }
}