#pragma GCC optimize("Ofast")

#include "bits/stdc++.h"


#define rep(i, n) for (int i = 0; i < (n); ++i)
#define rep1(i, n) for (int i = 1; i < (n); ++i)
#define rep1n(i, n) for (int i = 1; i <= (n); ++i)
#define repr(i, n) for (int i = (n) - 1; i >= 0; --i)
//#define pb push_back
#define eb emplace_back
#define all(a) (a).begin(), (a).end()
#define rall(a) (a).rbegin(), (a).rend()
#define each(x, a) for (auto &x : a)
#define ar array
#define vec vector
#define range(i, n) rep(i, n)

using namespace std;

using ll = long long;
using ull = unsigned long long;
using ld = long double;
using str = string;
using pi = pair<int, int>;
using pl = pair<ll, ll>;

using vi = vector<int>;
using vl = vector<ll>;
using vpi = vector<pair<int, int>>;
using vvi = vector<vi>;

int Bit(int mask, int b) { return (mask >> b) & 1; }

template<class T>
bool ckmin(T &a, const T &b) {
    if (b < a) {
        a = b;
        return true;
    }
    return false;
}

template<class T>
bool ckmax(T &a, const T &b) {
    if (b > a) {
        a = b;
        return true;
    }
    return false;
}

// [l, r)
template<typename T, typename F>
T FindFirstTrue(T l, T r, const F &predicat) {
    --l;
    while (r - l > 1) {
        T mid = l + (r - l) / 2;
        if (predicat(mid)) {
            r = mid;
        } else {
            l = mid;
        }
    }
    return r;
}


template<typename T, typename F>
T FindLastFalse(T l, T r, const F &predicat) {
    return FindFirstTrue(l, r, predicat) - 1;
}

const int INFi = 2e9;
const ll INF = 2e18;


void solve() {
    int n; cin >> n;
    vi l(n), r(n);
    rep(i, n) cin >> l[i] >> r[i];
    rep(i, n) r[i]++;

    vpi up, down;

    up.emplace_back(0, l[0]);
    for(int i = 1; i < n; ++i) {
        if (r[i] > r[i - 1]) {
            up.emplace_back(i, r[i - 1]);
        }
    }
    for(int i = 0; i < n; ++i) {
        if (i + 1 == n || l[i + 1] > l[i]) {
            down.emplace_back(i + 1, l[i]);
        }
    }
    for(auto &[x, y] : up) {
        x++;
    }

    int usz = up.size();
    int dsz = down.size();
    vi lu(usz), ru(usz);

    int lptr = 0;
    int rptr = 0;
    rep(i, up.size()) {
        while (rptr < down.size() && down[rptr].second <= up[i].second) rptr++;
        while (lptr < down.size() && down[lptr].first < up[i].first) lptr++;
        lu[i] = lptr;
        ru[i] = rptr;
    }

    int ans = max(usz, dsz);
    vi dp(usz);
    int ls = -INFi, ms = -INFi;
    int j = 0;
    rep(i, up.size()) {
        while (j < i && ru[j] <= lu[i]) {
            ckmax(ls, dp[j] - ru[j]);
            j++;
        }

        dp[i] = 1 + lu[i];
        ckmax(dp[i], 1 + ls + lu[i]);
        ckmax(dp[i], 1 + ms);
        ckmax(ms, dp[i]);
        ckmax(ans, dp[i] + dsz - ru[j]);
    }

    cout << ans << '\n';
}

signed main() {
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cout << setprecision(12) << fixed;
    int t = 1;

    cin >> t;
    rep(i, t) {
        solve();
    }
    return 0;
}