#include <bits/stdc++.h>
using namespace std;
void sol() {
    int n;
    cin >> n;
    deque<array<int, 2>> dq;
    int ans = 0;
    for(int i = 0; i < n; i++) {
        int l, r;
        cin >> l >> r;
        while(!dq.empty() && dq.front()[0] < l) {
            dq.pop_front();
        }

        if(dq.empty()) {
            ans += 1;
            dq.push_back({l, r});
        } else {
            l = dq.back()[1] + 1;
            if(l <= r){
                ans += 1;
                dq.push_back({l, r});
            }
        }
    }

    cout << ans << endl;
}

int main() {
    cin.tie(0)->ios::sync_with_stdio(0);
    int tc = 1;
    cin >> tc;
    while(tc--){
        sol();
    }
    return 0;
}