1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
//Jan Tabaszewski
#include <bits/stdc++.h>
using namespace std;
#define PII pair<int, int>
#define VI vector<int>
#define VPII vector<PII>
#define LL long long
#define LD long double
#define f first
#define s second
#define MP make_pair
#define PB push_back
#define endl '\n'
#define ALL(c) (c).begin(), (c).end()
#define SIZ(c) (int)(c).size()
#define REP(i, n) for(int i = 0; i < (int)(n); ++i)
#define FOR(i, b, e) for(int i = (b); i <= (int)(e); ++i)
#define FORD(i, b, e) for(int i = (b); i >= (int)(e); --i)
#define ll LL
#define st f
#define nd s
#define pb PB
#define mp MP
#define eb emplace_back
#define siz(c) SIZ(c)
const int inf = 1e9+7;
const ll INF = 1e18L+7;

#define sim template<class n
sim, class s> ostream & operator << (ostream &p, pair<n, s> x)
{return p << "<" << x.f << ", " << x.s << ">";}
sim> auto operator << (ostream &p, n y) ->
typename enable_if<!is_same<n, string>::value, decltype(y.begin(), p)>::type 
{int o = 0; p << "{"; for(auto c: y) {if(o++) p << ", "; p << c;} return p << "}";}
void dor() {cerr << endl;}
sim, class...s> void dor(n p, s...y) {cerr << p << " "; dor(y...);}
sim, class s> void mini(n &p, s y) {if(p>y) p = y;}
sim, class s> void maxi(n &p, s y) {if(p<y) p = y;}
#ifdef DEB
#define debug(...) dor(__FUNCTION__, ":", __LINE__, ": ", __VA_ARGS__)
#else
#define debug(...)
#endif 

#define I(x) #x " =", (x), " "
const int M = 1024 * 1024;

int D[3][2 * M];
int n, m;

void add(int ind, int p, int k)
{
	p += M;
	k += M;
	D[ind][p] = 1;
	D[ind][k] = 1;
	while (p / 2 != k / 2)
	{
		if (p % 2 == 0)
		{
			D[ind][p + 1] = 1;
		}
		p /= 2;
		if (k % 2 == 1)
		{
			D[ind][k - 1] = 1;
		}
		k /= 2;
	}
}

int get(int ind, int v)
{
	v += M;
	int r = D[ind][v];
	while (v > 1)
	{
		v /= 2;
		r |= D[ind][v];
	}
	return r;
}

int32_t main()
{
	//ios_base::sync_with_stdio(0);
	//cin.tie(NULL);
	scanf("%d%d", &n, &m);
	FOR(i, 1, m)
	{
		int a, b, c;
		scanf("%d%d%d", &a, &b, &c);
		add(c - 1, a, b);
	}
	int r = 0;
	FOR(i, 1, n)
	{
		r += get(0, i) == 1 && get(1, i) == 1 && get(2, i) == 0;
	}
	printf("%d\n", r);
}