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
ans = INFTY
dist = {}
visit = set()
que = [(0,1,0)]
dist[(1,0)] = 0
while que:
    t,v,c = heapq.heappop(que)
    if (v,c) in dist and dist[(v,c)]<t:continue
    if (v,c) in visit:continue
    visit.add((v,c))
    for u,dc,dt in G[v]:
        if (u,c-dc) in visit:continue
        if c>=dc:
            nc = c-dc
            nt = t+dt
            if nt<dist.get((u,nc),INFTY):
                dist[(u,nc)] = nt
                if u==N:
                    ans = min(ans,nt)
                heapq.heappush(que,(nt,u,nc))
        else:
            k = (dc-c+X-1)//X
            nc = c+k*X-dc
            nt = t+k+dt
            if nt<dist.get((u,nc),INFTY):
                dist[(u,nc)] = nt
                if u==N:
                    ans = min(ans,nt)
                heapq.heappush(que,(nt,u,nc))
if ans==INFTY:
    print(-1)
else:
    print(ans)