from collections import deque, defaultdict, Counter
from bisect import bisect_left, bisect_right, insort
from itertools import permutations, combinations, groupby
from heapq import heappop, heappush
import math, sys
input = lambda: sys.stdin.readline().rstrip("\r\n")
def printl(li, sep=" "): print(sep.join(map(str, li)))
def yn(flag): print(Yes if flag else No)
_int = lambda x: int(x)-1
MOD = 998244353 #10**9+7
INF = 1<<60
Yes, No = "Yes", "No"

N, M, Q = map(int, input().split())
A = list(map(int, input().split()))
q = []
for _ in range(M):
    u, v, w = map(int, input().split())
    u, v = u-1, v-1
    q.append((w, u, v))
QI = [[] for _ in range(N)]

SHIFT = 18
MASK = (1<<SHIFT)-1
ans = [-1]*Q
for qi in range(Q):
    s, c = map(int, input().split())
    if c == 1:
        ans[qi] = 0
    else:
        heappush(QI[s-1], c<<SHIFT|qi)

q.sort()

S = [set([A[i]]) for i in range(N)]
from atcoder.dsu import DSU
D = DSU(N)
for w, u, v in q:
    if D.same(u, v): continue
    pu = D.leader(u)
    pv = D.leader(v)
    su = S[pu]
    sv = S[pv]
    qu = QI[pu]
    qv = QI[pv]
    D.merge(u, v)
    if len(su) > len(sv):
        while sv:
            a = sv.pop()
            su.add(a)
        rs = su
    else:
        while su:
            a = su.pop()
            sv.add(a)
        rs = sv
    if len(qu) > len(qv):
        while qv:
            a = heappop(qv)
            heappush(qu, a)
        rq = qu
    else:
        while qu:
            a = heappop(qu)
            heappush(qv, a)
        rq = qv
    p = D.leader(u)
    S[p] = rs
    QI[p] = rq
    while rq:
        e = heappop(rq)
        if len(rs) >= e>>SHIFT:
            ans[e&MASK] = w
        else:
            heappush(rq, e)
            break
printl(ans, "\n")