#include <algorithm>
#include <bitset>
#include <cassert>
#include <chrono>
#include <complex>
#include <cstring>
#include <iomanip>
#include <iostream>
#include <map>
#include <queue>
#include <random>
#include <set>
#include <stack>
#include <unordered_set>
#include <vector>
using namespace std;
// BEGIN NO SAD
#define rep(i, a, b) for(int i = a; i < (b); ++i)
#define trav(a, x) for(auto& a : x)
#define all(x) x.begin(), x.end()
#define sz(x) (int)(x).size()
#define derr if(1) cerr
typedef vector<int> vi;
// END NO SAD
typedef long long ll;
typedef pair<int, int> pii;
typedef vector<vector<ll>> matrix;
typedef pair<int, pii> state;
struct statement {
int t, person, work, orig;
bool operator<(statement& s) {
return t < s.t;
}
};
int n, m;
statement l[100005];
int earliest[100005];
int latest[100005];
bool can(int thresh) {
memset(earliest, 1, sizeof(earliest));
memset(latest, -1, sizeof(latest));
int lastt = -1;
int lastclaim = -1;
// first check that everyone claims the same number of people
for(int i = 0; i < m; i++) {
if(l[i].orig >= thresh) continue;
if(l[i].work > n) return false;
if(l[i].t == lastt && l[i].work != lastclaim) return false;
lastt = l[i].t;
lastclaim = l[i].work;
earliest[l[i].person] = min(earliest[l[i].person], i);
latest[l[i].person] = i;
}
set<int> working; // working
set<pii> preworking;
int postworking = 0; // working
int flexible = 0;
set<pii> preempt; // working
for(int i = 1; i <= n; i++) {
if(earliest[i] <= 1e6) preworking.insert({earliest[i], i});
else flexible++;
}
for(int i = 0; i < m;) {
if(l[i].orig >= thresh) {
i++;
continue;
}
int j = i;
while(j < m && l[i].t == l[j].t) j++;
for(int k = i; k < j; k++) {
if(l[k].orig >= thresh) continue;
// if it is their first statement, they must start working now
if(earliest[l[k].person] == k) {
preworking.erase({earliest[k], k});
preempt.erase({earliest[k], k});
working.insert(k);
}
}
while(sz(working) + postworking + sz(preempt) < l[i].work) {
if(sz(preworking)) {
preempt.insert(*preworking.begin());
preworking.erase(preworking.begin());
}
else if(flexible) {
postworking++;
flexible--;
}
else {
return false;
}
}
while(sz(working) + postworking + sz(preempt) > l[i].work) {
if(postworking > 0) {
postworking--;
}
else if(sz(preempt) && flexible) {
preworking.insert(*preempt.begin());
preempt.erase(preempt.begin());
flexible--;
}
else {
return false;
}
}
// if it is their last statement, they are post-working now
for(int k = i; k < j; k++) {
if(l[k].orig >= thresh) continue;
// if it is their first statement, they must start working now
if(latest[l[k].person] == k) {
working.erase(k);
postworking++;
}
}
i = j;
}
return true;
}
void rsolve() {
cin >> n >> m;
for(int i = 0; i < m; i++) {
l[i].orig = i;
cin >> l[i].t >> l[i].person >> l[i].work;
l[i].work++;
}
sort(l, l+m);
int lhs = 0;
int rhs = m;
while(lhs < rhs) {
int mid = (lhs+rhs+1)/2;
if(can(mid)) lhs = mid;
else rhs = mid - 1;
}
cout << lhs << "\n";
}
void solve() {
int t;
cin >> t;
while(t--) rsolve();
}
// are there edge cases (N=1?)
// are array sizes proper (scaled by proper constant, for example 2* for koosaga tree)
// integer overflow?
// DS reset properly between test cases
int main() {
ios_base::sync_with_stdio(false);
cin.tie(NULL); cout.tie(NULL);
solve();
}
