import sys, time, random
from collections import deque, Counter, defaultdict
input = lambda: sys.stdin.readline().rstrip()
ii = lambda: int(input())
mi = lambda: map(int, input().split())
li = lambda: list(mi())
inf = 2 ** 61 - 1
mod = 998244353
import heapq
def Dijkstra(s, graph):
    n = len(graph)
    dist = [inf] * n
    dist[s] = 0
    hq = [(0, s)]
    heapq.heapify(hq)
    while hq:
        c, now = heapq.heappop(hq)
        
        if c > dist[now]:
            continue
        for to, cost in graph[now]:
            if dist[now] + cost < dist[to]:
                dist[to] = cost + dist[now]
                heapq.heappush(hq, (dist[to], + to))
    return dist
n, m, q = mi()
assert 1 <= n <= 10 ** 3 and 1 <= m <= 10 ** 3 and 1 <= q <= 10 ** 3
graph = [[] for _ in range(n)]
EDGE = []
for _ in range(m):
    u, v, c = mi()
    assert 1 <= u <= n and 1 <= v <= n and -10 ** 3 <= c <= 10 ** 3
    assert u != v
    u -= 1
    v -= 1
    c *= -1
    EDGE.append((u, v, c))
    graph[u].append((v, c))
    
#ベルマンフォード法
dist = [inf] * n
dist[0] = 0
for _ in range(n):
    for j in range(n):
        for to, c in graph[j]:
            if dist[to] > dist[j] + c:
                dist[to] = dist[j] + c

for i in range(n):
    for to, c in graph[j]:
        assert dist[to] <= dist[j] + c
graph2 = [[] for _ in range(n)]
EDGE2 = []
d1 = dist[n - 1]
for u, v, c in EDGE:
    assert c + dist[u] - dist[v] >= 0
    EDGE2.append((u, v, c + dist[u] - dist[v]))
    graph2[u].append((v, c + dist[u] - dist[v]))
onoff = [1] * m
E = li()
for e in E:
    assert 1 <= e <= m
    e -= 1
    if onoff[e]:
        onoff[e] = 0
        graph2[EDGE2[e][0]].remove((EDGE2[e][1], EDGE2[e][2]))
    else:
        onoff[e] = 1
        graph2[EDGE2[e][0]].append((EDGE2[e][1], EDGE2[e][2]))
    dist = Dijkstra(0, graph2)
    if dist[n - 1] == inf:
        print('NaN')
    else:
        print(-(dist[n - 1] + d1))