from heapq import heappop, heappush
INF = float("inf")

def dijkstra(graph, n, s):
    d = [INF] * n
    rem = [0] * n

    d[s] = 0
    q = [(0, s)]

    while q:
        time, v = heappop(q)
        if d[v] < time: continue
        for nv, value, t in graph[v]:
            cost = t
            wt = 0
            if rem[v] < value:
                wt = -(-(value-rem[v])//x)
                cost += wt
            
            if d[nv] > d[v] + cost:
                d[nv] = d[v] + cost
                rem[nv] = wt*x-value
                heappush(q, (d[nv], nv))
    return d

n, m, x = map(int, input().split())
g = [[] for _ in range(n)]
for _ in range(m):
    u, v, c, t = map(int, input().split())
    g[u-1].append((v-1, c, t))
    g[v-1].append((u-1, c, t))

res = dijkstra(g, n, 0)
print(-1 if res[-1] == INF else res[-1])