from bisect import *

N, B = map(int, input().split())
XYP = [tuple(map(int, input().split())) for _ in range(N)]
XYP.sort(key=lambda k: k[0])
ans = 0

for i in range(N):
    Xi, _, _ = XYP[i]
    
    for j in range(i, N):
        Xj, _, _ = XYP[j]
        YP = []
        
        for k in range(N):
            Xk, Yk, Pk = XYP[k]
            
            if Xi<=Xk<=Xj:
                YP.append((Yk, Pk))
        
        YP.sort(key=lambda k: k[0])
        YP += [('a', 'a')]
        cnt = []
        point = []
        c = 0
        p = 0
        
        for i in range(len(YP)-1):
            c += 1
            p += YP[i][1]
            
            if YP[i][0]!=YP[i+1][0]:
                cnt.append(c)
                point.append(p)
                c = 0
                p = 0
        
        c_acc = [0]
        p_acc = [0]
        
        for cnt_i in cnt:
            c_acc.append(c_acc[-1]+cnt_i)
        
        for point_i in point:
            p_acc.append(p_acc[-1]+point_i)
        
        for k in range(len(c_acc)):
            mark = bisect_right(p_acc, p_acc[k]+B)
            ans = max(ans, c_acc[mark-1]-c_acc[k])
    
print(ans)