N,V,L = map(int,input().split())
A = [(0,0,0)]+[list(map(int,input().split())) for _ in range(N)]+[(L,0,0)]
INFTY = 10**13
dp = [[INFTY for _ in range(V+1)] for _ in range(N+2)]
for j in range(V+1):
    dp[0][j] = 0
for i in range(1,N+2):
    x0,v0,w0 = A[i-1]
    x1,v1,w1 = A[i]
    dx = x1-x0
    for j in range(V-dx+1):
        dp[i][j] = dp[i-1][j+dx]
        if j+dx>=v0:
            dp[i][j] = min(dp[i][j],dp[i-1][j+dx-v0]+w0)
ans = min(dp[N+1])
if ans>=INFTY:
    print(-1)
else:
    print(ans)