import heapq

N, M, X=map(int, input().split())
edge=[[] for i in range(N)]
for i in range(M):
  u, v, C, T=map(int, input().split())
  u-=1; v-=1
  edge[u].append((v, C, T))
  edge[v].append((u, C, T))

d=[]
timeMIN=[None for i in range(N)]
heapq.heapify(d)

# 各タプルは (時間, - 残りのお金, 頂点) で入れる
heapq.heappush(d, (0, 0, 0))

while len(d)>0:
  t, mon, v=heapq.heappop(d)
  mon*=-1
  if timeMIN[v]==None: timeMIN[v]=t
  else: continue
  for nv, C, T in edge[v]:
    if timeMIN[nv]!=None: continue
    nt=t+T
    nmon=mon-C
    if nmon<0:
      nt+=(abs(nmon)+X-1)//X
      nmon%=X
    heapq.heappush(d, (nt, -nmon, nv))

print(timeMIN[N-1] if timeMIN[-1]!=None else -1)