n,v,l=map(int,input().split())
arr=[list(map(int,input().split())) for _ in range(n)]
n+=1
arr.append([l,0,0])
dp=[[10**18]*(v+1) for _ in range(n+1)]
dp[0][v]=0
now=0
for i in range(n):
    dist=arr[i][0]-now
    gas=arr[i][1]
    cost=arr[i][2]
    flag=False
    for j in range(v-dist,-1,-1):
        dp[i+1][j]=dp[i][j+dist]
        if dp[i+1][j]!=10**18:
            flag=True
    if flag==False:
        print(-1)
        break
    else:
        for j in range(v,-1,-1):
            dp[i+1][min(v,j+gas)]=min(dp[i+1][min(v,j+gas)],dp[i+1][j]+cost)
    now=arr[i][0]
else:
    print(min(dp[-1]))