import heapq
N,M,X = list(map(int,input().split()))
edge = [[] for _ in range(N)]
for _ in range(M):
    u,v,c,t = list(map(int,input().split()))
    u -= 1;v -= 1
    edge[u].append((v,c,t))
    edge[v].append((u,c,t))

q = [(0,0,0,0)]
INF = 10**18
visited = [INF] * N
while(q):
    v,time,money,now = heapq.heappop(q)

    if(visited[now] <= v):continue
    visited[now] = v

    for u,c,t in edge[now]:
        next_time = time + t
        next_money = money + c
        next_v = next_time + -(-next_money//X)
        heapq.heappush(q,(next_v,next_time,next_money,u))
print(visited[-1] if visited[-1] != INF else -1)