from collections import deque,defaultdict
N,M,X=map(int,input().split())
G=[[] for _ in range(N)]
C=defaultdict(int)
T=defaultdict(int)
for _ in range(M):
    u,v,c,t=map(int,input().split())
    u-=1;v-=1
    G[u].append(v)
    G[v].append(u)
    C[(u,v)]=c
    C[(v,u)]=c
    T[(u,v)]=t
    T[(v,u)]=t
vis=[(-1,-1) for _ in range(N)]
Q=deque()
Q.append((0,0,0))
while Q:
    now,c,t=Q.popleft()
    vis[now]=(c,t)
    for nxt in G[now]:
        if vis[nxt]==(-1,-1) or t+T[(now,nxt)]<vis[nxt][1]:
            Q.append((nxt,c+C[(now,nxt)],t+T[(now,nxt)]))
ans=(vis[N-1][0]+X-1)//X+vis[N-1][1]
print(ans if ans>0 else -1)