#include <bits/stdc++.h>
using namespace std;

typedef long long   signed int LL;
typedef long long unsigned int LU;

#define incID(i, l, r) for(int i = (l)    ; i <  (r); i++)
#define incII(i, l, r) for(int i = (l)    ; i <= (r); i++)
#define decID(i, l, r) for(int i = (r) - 1; i >= (l); i--)
#define decII(i, l, r) for(int i = (r)    ; i >= (l); i--)
#define  inc(i, n) incID(i, 0, n)
#define inc1(i, n) incII(i, 1, n)
#define  dec(i, n) decID(i, 0, n)
#define dec1(i, n) decII(i, 1, n)

#define inII(v, l, r) ((l) <= (v) && (v) <= (r))
#define inID(v, l, r) ((l) <= (v) && (v) <  (r))

#define PB push_back
#define EB emplace_back
#define MP make_pair
#define FI first
#define SE second
#define UB upper_bound
#define LB lower_bound
#define PQ priority_queue

#define  ALL(v)  v.begin(),  v.end()
#define RALL(v) v.rbegin(), v.rend()
#define  FOR(it, v) for(auto it =  v.begin(); it !=  v.end(); ++it)
#define RFOR(it, v) for(auto it = v.rbegin(); it != v.rend(); ++it)

template<typename T> bool   setmin(T & a, T b) { if(b <  a) { a = b; return true; } else { return false; } }
template<typename T> bool   setmax(T & a, T b) { if(b >  a) { a = b; return true; } else { return false; } }
template<typename T> bool setmineq(T & a, T b) { if(b <= a) { a = b; return true; } else { return false; } }
template<typename T> bool setmaxeq(T & a, T b) { if(b >= a) { a = b; return true; } else { return false; } }
template<typename T> T gcd(T a, T b) { return (b == 0 ? a : gcd(b, a % b)); }
template<typename T> T lcm(T a, T b) { return a / gcd(a, b) * b; }

// ---- ----

int n, b, x[400], y[400], p[400];
vector<int> vx, vy;
map<int, int> mx, my;
int sn[401][401], sp[401][401];

int main() {
	cin >> n >> b;
	inc(i, n) { cin >> x[i] >> y[i] >> p[i]; }
	
	inc(i, n) { vx.PB(x[i]); }
	inc(i, n) { vy.PB(y[i]); }
	sort(ALL(vx)); int xs = unique(ALL(vx)) - vx.begin();
	sort(ALL(vy)); int ys = unique(ALL(vy)) - vy.begin();
	inc(i, xs) { mx[vx[i]] = i; }
	inc(i, ys) { my[vy[i]] = i; }
	inc(i, n) {
		sn[mx[x[i]] + 1][my[y[i]] + 1] = 1;
		sp[mx[x[i]] + 1][my[y[i]] + 1] = p[i];
	}
	
	inc1(i, xs) {
	inc1(j, ys) {
		sn[i][j] += sn[i - 1][j];
		sp[i][j] += sp[i - 1][j];
	}
	}
	inc1(i, xs) {
	inc1(j, ys) {
		sn[i][j] += sn[i][j - 1];
		sp[i][j] += sp[i][j - 1];
	}
	}
	
	int ans = 0;
	inc(i2, xs + 1) {
	inc(i1, i2    ) {
		int j1 = 0;
		inc(j2, ys + 1) {
			#define RN (sn[i2][j2] - sn[i1][j2] - sn[i2][j1] + sn[i1][j1])
			#define RP (sp[i2][j2] - sp[i1][j2] - sp[i2][j1] + sp[i1][j1])
			while(RP > b) { j1++; }
			if(j1 == j2) { continue; }
			setmax(ans, RN);
		}
	}
	}
	
	cout << ans << endl;
	
	return 0;
}