from bisect import *
N = int(input())
A = sorted((tuple(map(int, input().split())) for _ in range(N)),
        key=lambda x: (x[0],-x[1]))
P = sorted((t[1],i) for i,t in enumerate(A))
B = [0]*(N+2)
def U(i, v):
    while i <= N:
        B[i] = max(B[i], v)
        i += i&-i
def Q(i):
    v = 0
    while i > 0:
        v = max(v, B[i])
        i -= i&-i
    return v
for i in range(N)[::-1]:
    _, b, c = A[i]
    j = N-bisect(P, (b,N))
    v = Q(j)
    j = N-bisect(P, (b,i))+1
    U(j, v+c)
print(max(B))