"""
sliding window aggrigation
モノイドのqueueを管理する
fold_all: すべてをたたみこむ
popleft
append
"""
from itertools import accumulate
from collections import deque
class SWAG:
    def __init__(self, operator_M, e_M):
        self.op_M = operator_M
        self.op_rev = lambda x,y: self.op_M(y,x)
        self.e_M = e_M
        self.q = deque([])
        self.accL = []
        self.accR = e_M
        self.L = self.R = 0

    def build(self,lst):
        self.q = deque(lst)
        self.L = len(lst)
        self.accL = list(accumulate(reversed(lst),self.op_rev))

    def __len__(self):
        return self.L + self.R

    def fold_all(self):
        if self.L: return self.op_M(self.accL[-1],self.accR)
        else: return self.accR

    def append(self,x):
        self.q.append(x)
        self.accR = self.op_M(self.accR,x)
        self.R += 1
    
    def popleft(self):
        if self.L:
            self.accL.pop()
            self.L -= 1
            return self.q.popleft()
        elif self.R:
            v = self.q.popleft()
            self.L,self.R = self.R-1,0
            self.accL = list(accumulate(reversed(self.q),self.op_rev))
            self.accR = self.e_M
            return v
        else:
            assert 0

    def __repr__(self):
        return "{}\naccL:{}, accR:{}".format(self.q,self.accL,self.accR)




# coding: utf-8
# Your code here!
import sys
readline = sys.stdin.readline
read = sys.stdin.read

n,V,L = [int(i) for i in readline().split()]
xvw = [[int(i) for i in readline().split()] for _ in range(n)]

n += 1
xvw.append([L,0,0])

INF = 10**18
dp = [INF]*(V+1)
dp[V] = 0

D = [xvw[0][0]] + [xvw[i+1][0]-xvw[i][0] for i in range(n-1)] + [L - xvw[-2][0]]
for (x,v,w),d in zip(xvw,D):
    ndp = [INF]*(V+1)
    for i in range(V+1-d):
        ndp[i] = dp[i+d]
    for i in range(V,v-1,-1):
        ndp[i] = min(ndp[i],ndp[i-v]+w)
    dp = ndp
    #print(dp)

x = min(dp)
if x == INF:
    print(-1)
else:
    print(x)