n,m,k=map(int,input().split())
g = [['-']*n for _ in range(n)]
v=[]
for _ in range(m):
    i,j,c=map(int,input().split())
    g[i-1][j-1] = c
    g[j-1][i-1] = c
    v.append((c,i-1,j-1))
p = list(range(len(g)))
s = [1]*len(g)
def f(x):
    if x == p[x]:
        return x
    p[x] = f(p[x])
    return p[x]
def u(x, y):
    x = f(x)
    y = f(y)
    if s[x] > s[y]:
        x, y = y, x
    p[x] = p[y]
    s[y] += s[x]
e = {(int(c),i,j) for i,r in enumerate(g)
        for j,c in enumerate(r) if c != '-'}
pp =0
for _ in range(k):
    c,i,j=v[int(input())-1]
    e.remove((c,i,j))
    e.remove((c,j,i))
    e.add((0,i,j))
    e.add((0,j,i))
    pp += c
e = sorted(e)
r = 0
d = 0
for c,i,j in e:
    if f(i)==f(j):
        r += c
        continue
    u(i,j)
    d += c
print((r-d)//2)