import heapq
N,M,X = map(int,input().split())
G = {i:[] for i in range(1,N+1)}
for _ in range(M):
    u,v,c,t = map(int,input().split())
    G[u].append((v,c,t))
    G[v].append((u,c,t))
INFTY = 10**12
dist = [INFTY]*(N+1)
visit = [0]*(N+1)
que = [(0,1,0)]
dist[1] = 0
while que:
    t,v,c = heapq.heappop(que)
    if t>dist[v]:continue
    visit[v] = 1
    for u,dc,dt in G[v]:
        if visit[u]==1:continue
        if c>=dc:
            nc = c-dc
            nt = t+dt
            if nt<dist[u]:
                dist[u] = nt
                heapq.heappush(que,(nt,u,nc))
        else:
            k = (dc-c+X-1)//X
            nc = c+k*X-dc
            nt = t+dt+k
            if nt<dist[u]:
                dist[u] = nt
                heapq.heappush(que,(nt,u,nc))
if dist[N]==INFTY:
    print(-1)
else:
    print(dist[N])