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#include <bits/stdc++.h>
using namespace std;
#define int long long
#define mod 998244353

int32_t main()
{
    ios::sync_with_stdio(0);
    cin.tie(0);

    int t;
    cin>>t;

    while(t--)
    {
        int n,m;
        cin>>n>>m;
        int l[m];
        int r[m];
        for(int i=0;i<m;i++){cin>>l[i]>>r[i];l[i]--;r[i]--;}

        vector<int> opens[n+1];
        vector<int> closes[n+1];

        for(int i=0;i<m;i++)
        {
            opens[l[i]].push_back(i);
            closes[r[i]].push_back(i);
        }

        set<pair<int,int>> s; //(close,i)

        int dp[n+1];
        dp[n]=0;
        for(int i=n-1;i>=0;i--)
        {
            for(auto x:closes[i]){s.insert({r[x],x});}
            dp[i]=dp[i+1];
            if(!s.empty())
            {
                dp[i]=max(dp[i],(int)(s.size())+dp[(*(s.rbegin())).first+1]);
            }

            for(auto x:opens[i]){s.erase({r[x],x});}

        }
        cout<<dp[0]<<"\n";
    }







   return 0;
}