#include <cstdio>
#include <vector>
#include <algorithm>
#include <set>
const int MN = 100005;
const int MS = 524288;
const int Inf = 0x7fffffff;
int N, M, Q, cnt;
int w[MN * 2];
std::vector<int> G[MN], T[MN * 2];
std::multiset<int> S[MN * 2];
int dfn[MN * 2], low[MN], dfc;
int stk[MN], tp;
void Tarjan(int u) {
low[u] = dfn[u] = ++dfc;
stk[++tp] = u;
for (auto v : G[u]) {
if (!dfn[v]) {
Tarjan(v);
low[u] = std::min(low[u], low[v]);
if (low[v] == dfn[u]) {
++cnt;
for (int x = 0; x != v; --tp) {
x = stk[tp];
T[cnt].push_back(x);
T[x].push_back(cnt);
}
T[cnt].push_back(u);
T[u].push_back(cnt);
}
}
else low[u] = std::min(low[u], dfn[v]);
}
}
int idf[MN * 2], faz[MN * 2], siz[MN * 2], dep[MN * 2], son[MN * 2], top[MN * 2];
void DFS0(int u, int fz) {
faz[u] = fz, dep[u] = dep[fz] + 1, siz[u] = 1;
for (auto v : T[u]) if (v != fz) {
DFS0(v, u);
siz[u] += siz[v];
if (siz[son[u]] < siz[v]) son[u] = v;
}
}
void DFS1(int u, int fz, int tp) {
dfn[u] = ++dfc, idf[dfc] = u, top[u] = tp;
if (son[u]) DFS1(son[u], u, tp);
for (auto v : T[u])
if (v != fz && v != son[u])
DFS1(v, u, v);
}
#define li (i << 1)
#define ri (i << 1 | 1)
#define mid ((l + r) >> 1)
#define ls li, l, mid
#define rs ri, mid + 1, r
int dat[MS];
void Build(int i, int l, int r) {
if (l == r) { dat[i] = w[idf[l]]; return ; }
Build(ls), Build(rs);
dat[i] = std::min(dat[li], dat[ri]);
}
void Mdf(int i, int l, int r, int p, int x) {
if (l == r) { dat[i] = x; return ; }
if (p <= mid) Mdf(ls, p, x);
else Mdf(rs, p, x);
dat[i] = std::min(dat[li], dat[ri]);
}
int Qur(int i, int l, int r, int a, int b) {
if (r < a || b < l) return Inf;
if (a <= l && r <= b) return dat[i];
return std::min(Qur(ls, a, b), Qur(rs, a, b));
}
int main() {
scanf("%d%d%d", &N, &M, &Q);
for (int i = 1; i <= N; ++i)
scanf("%d", &w[i]);
cnt = N;
for (int i = 1; i <= M; ++i) {
int u, v;
scanf("%d%d", &u, &v);
G[u].push_back(v);
G[v].push_back(u);
}
Tarjan(1), DFS0(1, 0), dfc = 0, DFS1(1, 0, 1);
for (int i = 1; i <= N; ++i) if (faz[i])
S[faz[i]].insert(w[i]);
for (int i = N + 1; i <= cnt; ++i)
w[i] = *S[i].begin();
Build(1, 1, cnt);
for (int q = 1; q <= Q; ++q) {
char opt[3]; int x, y;
scanf("%s%d%d", opt, &x, &y);
if (*opt == 'C') {
Mdf(1, 1, cnt, dfn[x], y);
if (faz[x]) {
int u = faz[x];
S[u].erase(S[u].lower_bound(w[x]));
S[u].insert(y);
if (w[u] != *S[u].begin()) {
w[u] = *S[u].begin();
Mdf(1, 1, cnt, dfn[u], w[u]);
}
}
w[x] = y;
}
else {
int Ans = Inf;
while (top[x] != top[y]) {
if (dep[top[x]] < dep[top[y]])
std::swap(x, y);
Ans = std::min(Ans, Qur(1, 1, cnt, dfn[top[x]], dfn[x]));
x = faz[top[x]];
}
if (dfn[x] > dfn[y]) std::swap(x, y);
Ans = std::min(Ans, Qur(1, 1, cnt, dfn[x], dfn[y]));
if (x > N) Ans = std::min(Ans, w[faz[x]]);
printf("%d\n", Ans);
}
}
return 0;
}