from collections import defaultdict
from heapq import heappush, heappop

N, M, X = map(int, input().split())
adj = defaultdict(list)
for _ in range(M):
    u, v, C, T = map(int, input().split())
    u -= 1
    v -= 1
    adj[u].append((v, C, T))
    adj[v].append((u, C, T))

q = [(0, 0, 0)]  # (time, money, 頂点)
used = set()
while q:
    time, money, v = heappop(q)
    money = -money
    if v == N-1:
        print(time)
        exit()
    if v in used: continue
    used.add(v)

    for to, c, t in adj[v]:
        if to in used: continue
        if money >= c:
            heappush(q, (time+t, -(money-c), to))
        else:
            lack = c - money
            d = (lack + X - 1) // X
            m2 = money + X * d - c
            t2 = time + d + t
            heappush(q, (t2, -m2, to))

print(-1)