import sys, math
sys.setrecursionlimit(10**8)
sys.set_int_max_str_digits(0)
INF = 1e18
MOD = 998244353
from bisect import bisect_left, bisect_right
from collections import deque, defaultdict, Counter
from itertools import product, combinations, permutations, groupby, accumulate
from heapq import heapify, heappop, heappush
input = sys.stdin.readline
def I():   return input().rstrip()
def II():  return int(input().rstrip())
def IS():  return input().rstrip().split()
def MII(): return map(int, input().rstrip().split())
def LI():  return list(input().rstrip())
def TII(): return tuple(map(int, input().rstrip().split()))
def LII(): return list(map(int, input().rstrip().split()))
def LSI(): return list(map(str, input().rstrip().split()))
def GMI(): return list(map(lambda x: int(x) - 1, input().rstrip().split()))
def kiriage(a, b): return (a+b-1)//b

N, M, X = MII()
G = [list() for _ in range(N + 1)]
for i in range(M):
    u, v, c, t = MII()
    G[u].append((v, X*t + c))
    G[v].append((u, X*t + c))

kakutei = [False] * (N + 1)
dist = [INF] * (N + 1)
dist[1] = 0
que = []
heappush(que, (0, 1))
while que:
    curr_dist, pos = heappop(que)
    if kakutei[pos]:
        continue
    kakutei[pos] = True
    for nex, kyori in G[pos]:
        if kakutei[nex]:
            continue
        if dist[nex] > curr_dist + kyori:
            dist[nex] = curr_dist + kyori
            heappush(que, (dist[nex], nex))

if dist[-1] == INF:
    print(-1)
else:
    ans = kiriage(dist[-1], X)
    print(ans)