n,v,l = map(int,input().split())
xvw = [[int(i) for i in input().split()] for j in range(n)]

dp = [10**15]*(v+1)
dp[v] = 0
pos = 0
#print(dp)
for i in range(n):
    x,vi,wi = xvw[i]
    dis = x-pos
    for j in range(v+1):
        if dis > j:
            dp[j] = 10**15
        else:
            dp[j-dis] = dp[j]
            dp[j] = 10**15
    #print(dis)
    #print(dp,111)
    for j in range(v+1):
        dp[min(v,j+vi)] = min(dp[j]+wi,dp[min(v,j+vi)])
    pos = x
    #print(dp,i)
#print(dp)
#exit()
if pos != l:
    dis = l-pos
    ans = 10**15
    for j in range(v+1):
        if dis <= j:
            ans = min(ans,dp[j])
else:
    ans = min(dp)

if ans >= 10**15:
    print(-1)
else:
    print(ans)