#include <bits/stdc++.h>
#define int long long
#define yes cout<<"YES\n";
#define no cout<<"NO\n";
#define pb push_back
#define pii pair<int,int>
#define str string
#define vec vector<int>
#define vecc vector<vector<int>>
#define f first
#define s second
using namespace std;
const int maxn = 1e6 + 1;
const int INF = 1e9 + 1;
const int mod = 1e9 + 7;
int binpow(int x, int n){
int ans = 1;
while(n){
if(n % 2 == 1) ans = ans * x % mod;
x = x * x % mod;
n /= 2;
}
return ans;
}
int a[maxn] , b[maxn] , n , m;
void solve(){
cin >> n >> m;
for (int i = 1; i <= m; i++) {
int c;
cin >> a[i] >> b[i] >> c;
}
int ans = 1e18;
for (int mask = 0; mask < (1 << m); mask++) {
int used[21] = {0};
for (int i = 1; i <= m; i++) {
int cur = a[i];
int dir = (mask >> (i - 1)) & 1;
if (dir == 0) {
while (cur != b[i]) {
used[cur]++;
cur++;
if (cur > n) cur = 1;
}
} else {
while (cur != b[i]) {
int p = cur - 1;
if (p == 0) p = n;
used[p]++;
cur = p;
}
}
}
int d = 0;
for (int i = 1; i <= n; i++) {
d = max(d, used[i]);
}
ans = min(ans, d);
}
cout << ans << '\n';
}
signed main() {
ios_base::sync_with_stdio(0),cin.tie(0);
// freopen("aplusb.in" , "r" , stdin);
// freopen("aplusb.out" , "w" , stdout);
int t = 1;
// cin >> t;
while(t--){
solve();
}
}
