n,b = map(int,input().split())
xyp = []
sx = set()
sy = set()
for _ in range(n):
    x,y,p = map(int,input().split())
    xyp.append((x,y,p))
    sx.add(x)
    sy.add(y)
*sx, = sorted(sx)
*sy, = sorted(sy)
zx = {si:i for i,si in enumerate(sx)}
zy = {si:i for i,si in enumerate(sy)}

lx = len(sx)
ly = len(sy)
cnt = [[0]*ly for _ in range(lx)]
pts = [[0]*ly for _ in range(lx)]
for x,y,p in xyp:
    cnt[zx[x]][zy[y]] += 1
    pts[zx[x]][zy[y]] += p

for i in range(lx):
    for j in range(1,ly):
        cnt[i][j] += cnt[i][j-1]
        pts[i][j] += pts[i][j-1]
for j in range(ly):
    for i in range(1,lx):
        cnt[i][j] += cnt[i-1][j]
        pts[i][j] += pts[i-1][j]

ans = 0
for x0 in range(lx):
    for y0 in range(ly):
        for x1 in range(x0,lx):
            y1 = ly-1
            while y0 <= y1 and (pts[x1][y1] - (pts[x0-1][y1] if x0 else 0) - (pts[x1][y0-1] if y0 else 0) + (pts[x0-1][y0-1] if x0 and y0 else 0)) > b:
                y1 -= 1
            if y0 > y1: break
            ans = max(ans, cnt[x1][y1] - (cnt[x0-1][y1] if x0 else 0) - (cnt[x1][y0-1] if y0 else 0) + (cnt[x0-1][y0-1] if x0 and y0 else 0))
print(ans)