import sys
input = lambda :sys.stdin.readline()[:-1]
ni = lambda :int(input())
na = lambda :list(map(int,input().split()))
yes = lambda :print("yes");Yes = lambda :print("Yes");YES = lambda : print("YES")
no = lambda :print("no");No = lambda :print("No");NO = lambda : print("NO")

#######################################################################

inf = -10**18
class SegmentTree:
    # 初期化処理
    # f : SegmentTreeにのせるモノイド
    # default : fに対する単位元
    def __init__(self, size, f=lambda x,y : max(x,y), default=inf):
        self.size = 2**(size-1).bit_length() # 簡単のため要素数Nを2冪にする
        self.default = default
        self.dat = [default]*(self.size*2) # 要素を単位元で初期化
        self.f = f
 
    def update(self, i, x):
        i += self.size
        self.dat[i] = self.f(self.dat[i],x)
        while i > 0:
            i >>= 1
            self.dat[i] = self.f(self.dat[i*2], self.dat[i*2+1])
 
    def query(self, l, r):
        l += self.size
        r += self.size
        lres, rres = self.default, self.default
        while l < r:
            if l & 1:
                lres = self.f(lres, self.dat[l])
                l += 1
 
            if r & 1:
                r -= 1
                rres = self.f(self.dat[r], rres) # モノイドでは可換律は保証されていないので演算の方向に注意
            l >>= 1
            r >>= 1
        res = self.f(lres, rres)
        return res
 
    def query2(self):
        s = 1
        #print(self.size)
        while s<self.size:
            #print(s)
            if self.dat[s*2]>self.dat[s*2+1]:
                s = s*2
            else:
                s = s*2+1
        return s-self.size

N = ni()
AB  = []
s = set([0])
for i in range(N):
    t,x,v = na()
    AB.append((x+t,t-x,v,i))
    s.add(t-x)
s = sorted(s)
d = {x:i for i, x in enumerate(s)}
m = len(s)
tree = SegmentTree(m)
tree.update(d[0], 0)
ans = 0
for a,b,v,i in sorted(AB):
    if a < 0:
        continue
    b = d[b]
    z = tree.query(0,b+1)
    #print(a,b,v,z)
    tree.update(b,z+v)
    ans = max(ans, z+v)
print(ans)