#include <bits/stdc++.h>
using namespace std;
const int M = 2e5 + 5;
int min(int x, int y) { return x < y ? x : y; }
void swap(int &x, int &y) { x ^= y ^= x ^= y; }
int n, m, q, w[M];
int read() {
  int x = 0, y = 1;
  char ch = getchar();
  while (ch < '0' || ch > '9') y = (ch == '-') ? -1 : 1, ch = getchar();
  while (ch >= '0' && ch <= '9') x = x * 10 + ch - '0', ch = getchar();
  return x * y;
}
int tot = 0, first[M];
struct Edge {
  int nxt, to;
} e[M << 1];
void add(int x, int y) {
  e[++tot] = (Edge){first[x], y};
  first[x] = tot;
}
int cnt;
vector<int> G[M];
multiset<int> nw[M];
namespace YuanFangShu {
int num = 0, top = 0, dfn[M], low[M], sta[M];
void Add(int x, int y) { G[x].push_back(y), G[y].push_back(x); }
void tarjan(int u) {
  dfn[u] = low[u] = ++num;
  sta[++top] = u;
  for (int i = first[u]; i; i = e[i].nxt) {
    int v = e[i].to;
    if (!dfn[v]) {
      tarjan(v), low[u] = min(low[u], low[v]);
      if (low[v] == dfn[u]) {
        cnt++;
        for (int x; x != v; top--) Add(x = sta[top], cnt);
        Add(u, cnt);
      }
    } else
      low[u] = min(low[u], dfn[v]);
  }
}
}  // namespace YuanFangShu
namespace Segment {
int minn[M << 2];
void pushup(int u) { minn[u] = min(minn[u << 1], minn[u << 1 | 1]); }
void Build(int u, int l, int r) {
  minn[u] = 1e9;
  if (l == r) return;
  int mid = (l + r) >> 1;
  Build(u << 1, l, mid), Build(u << 1 | 1, mid + 1, r);
}
void Change(int u, int l, int r, int x, int d) {
  if (l == r) return (void)(minn[u] = d);
  int mid = (l + r) >> 1;
  if (x <= mid)
    Change(u << 1, l, mid, x, d);
  else
    Change(u << 1 | 1, mid + 1, r, x, d);
  pushup(u);
}
int Query(int u, int l, int r, int L, int R) {
  if (l > R || r < L || L > R) return 1e9;
  if (L <= l && r <= R) return minn[u];
  int mid = (l + r) >> 1;
  return min(Query(u << 1, l, mid, L, R), Query(u << 1 | 1, mid + 1, r, L, R));
}
}  // namespace Segment
namespace ShuPou {
using namespace Segment;
int num = 0, de[M], sz[M], fa[M], dfn[M], son[M], top[M];
void dfs1(int u, int f) {
  de[u] = de[fa[u] = f] + 1;
  sz[u] = 1;
  for (int i = 0; i < G[u].size(); i++) {
    int v = G[u][i];
    if (v == f) continue;
    dfs1(v, u);
    sz[u] += sz[v];
    if (sz[v] > sz[son[u]]) son[u] = v;
  }
}
void dfs2(int u, int tp) {
  top[u] = tp;
  dfn[u] = ++num;
  if (son[u]) dfs2(son[u], tp);
  for (int i = 0; i < G[u].size(); i++) {
    int v = G[u][i];
    if (v == fa[u] || v == son[u]) continue;
    dfs2(v, v);
  }
}
int QUERY(int x, int y) {
  int res = 1e9;
  while (top[x] != top[y]) {
    if (de[top[x]] < de[top[y]]) swap(x, y);
    res = min(res, Query(1, 1, cnt, dfn[top[x]], dfn[x]));
    x = fa[top[x]];
  }
  if (de[x] < de[y]) swap(x, y);
  res = min(res, Query(1, 1, cnt, dfn[y], dfn[x]));
  if (y <= n)
    res = min(res, w[y]);
  else
    res = min(res, w[fa[y]]);
  return res;
}
void CHANGE(int x, int d) {
  nw[fa[x] - n].erase(nw[fa[x] - n].find(w[x]));
  w[x] = d;
  nw[fa[x] - n].insert(w[x]);
  Change(1, 1, cnt, dfn[fa[x]], *nw[fa[x] - n].begin());
}
void Init() {
  dfs1(n + 1, 0), dfs2(n + 1, n + 1);
  Build(1, 1, cnt);
  for (int i = 1; i <= n; i++) nw[fa[i] - n].insert(w[i]);
  for (int i = n + 1; i <= cnt; i++)
    Change(1, 1, cnt, dfn[i], *nw[i - n].begin());
}
}  // namespace ShuPou
using namespace ShuPou;
void solve() {
  n = read(), m = read(), q = read();
  cnt = n;
  w[0] = 1e9;
  for (int i = 1; i <= n; i++) w[i] = read();
  for (int i = 1; i <= m; i++) {
    int x = read(), y = read();
    add(x, y), add(y, x);
  }
  YuanFangShu::tarjan(1);
  Init();
  while (q--) {
    char opt[5];
    scanf("%s", opt);
    if (opt[0] == 'C') {
      int x = read(), w = read();
      CHANGE(x, w);
    } else {
      int x = read(), y = read();
      printf("%d\n", QUERY(x, y));
    }
  }
}
signed main() { solve(); }
