#Created on 2015/03/15 ans
import bisect

[N, B] = map(int, input().split())
X = []
Y = []
P = []
for _ in range(N) :
    [x, y, p] = map(int, input().split())
    X.append(x)
    Y.append(y)
    P.append(p)
    
xs = sorted(list(set(X)))
ys = sorted(list(set(Y)))

points = [[0]*len(xs) for _ in range(len(ys))]
counts = [[0]*len(xs) for _ in range(len(ys))]

for i in range(N) :
    x = bisect.bisect_left(xs, X[i])
    y = bisect.bisect_left(ys, Y[i])
    points[y][x] += P[i]
    counts[y][x] += 1
    
    
for i in range(len(ys)) :
    for j in range(len(xs)) :
        if i > 0 :
            points[i][j] += points[i-1][j]
            counts[i][j] += counts[i-1][j]
        if j > 0 :
            points[i][j] += points[i][j-1]
            counts[i][j] += counts[i][j-1]
        if i > 0 and j > 0 :
            points[i][j] -= points[i-1][j-1]
            counts[i][j] -= counts[i-1][j-1]
            
            
def get_sum(L, a, b, c, d) :
    ret = 0
    ret += L[c][d]
    if a > 0 : ret -= L[a-1][d]
    if b > 0 : ret -= L[c][b-1]
    if a > 0 and b > 0 : ret += L[a-1][b-1]
    return ret

ans = 0
#(i,j) (k, l)
for i in range(len(xs)) :
    for k in range(i, len(xs)) :
        j = 0
        for l in range(len(ys)) :
            p = get_sum(points, j, i, l, k)
            if p > B :
                while j <= l and p > B :
                    j += 1
                    if j <= l : p = get_sum(points, j, i, l, k)
            
            if j <= l and p <= B :
                ans = max(ans, get_sum(counts, j, i, l, k))
                

    

print(ans)