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#include <cstdio>
#include <algorithm>
using namespace std;
typedef long long LL;
const int N = 80005;
inline int getint() {
	int r = 0, k = 1; char c = getchar();
	for (; '0' > c || c > '9'; c = getchar()) if (c == '-') k = -1;
	for (; '0' <= c && c <= '9'; c = getchar()) r = r * 10 - '0' + c;
	return r * k;
}
char dst[1024]; int ptr;
inline void putint(int x) {
	for (; x; x /= 10)
		dst[++ptr] = x % 10;
	while (ptr) putchar(dst[ptr--]+'0');
	putchar('\n');
}
struct Edge {int to, next;} edge[N<<1];
int n, q, x, y, k, dep[N], top[N], A[N], B[N], T[N], cnte = 1, fat[N], hah[N], son[N], dfn[N], clo, tot, root[N<<2], h[N], lc[N*30], rc[N*30], siz[N*30], tim[N*30], val[N*30], fa[N*30];
inline void ins(int x, int y) {
	edge[++cnte].to = y;
	edge[cnte].next = h[x];
	h[x] = cnte;
}
inline void pu(int x) { siz[x] = siz[lc[x]] + siz[rc[x]] + tim[x]; }
inline void rotate(int x) {
	int y = fa[x], z = fa[y];
	if (z) {
	   if (rc[z]==y) rc[z] = x;
	   else lc[z] = x;
	}
	if (rc[y] == x) {
		fa[x] = z; fa[y] = x; fa[lc[x]] = y; fa[0] = 0;
		rc[y] = lc[x]; lc[x] = y;
		pu(y); pu(x);
	} else {
		fa[x] = z; fa[y] = x; fa[rc[x]] = y; fa[1] = 0;
		lc[y] = rc[x]; rc[x] = y;
		pu(y); pu(x);
	}
}
inline void splay(int x) {
	while (fa[x]) {
		int y = fa[x], z = fa[y];
		if (z) {
			if (lc[y] == x ^ lc[z] == y) rotate(x);
			else rotate(y);
		}
		rotate(x);
	}
}
void Insert(int &rt, int &x, int key, int father) {
	if (!x) {
		x = ++tot;
		val[tot] = key;
		fa[tot] = father;
		tim[tot] = siz[tot] = 1;
		splay(tot);
		rt = tot;
		return;
	} else {
		++siz[x];
		if (val[x] == key) {
			++tim[x];
			key = x;
			splay(key);
			rt = key;
			return;
		}
		if (val[x] < key) Insert(rt, rc[x], key, x);
		else Insert(rt, lc[x], key, x);
	}
}
inline void Delete(int &rt, int key) {
	for (int x = rt; x; ) {
		if (val[x] == key) {
			splay(x);
			rt = x;
			--siz[x]; --tim[x];
			return;
		}
		if (val[x] < key) x = rc[x];
		else x = lc[x];
	}
}
inline int CountGreater(int &rt, int key) {
	int x = rt, y = 0;
	while (x) {
		if (val[x] < key) { y = x; x = rc[x]; }
		else x = lc[x];
	}
	if (!y) return siz[rt];
	else {
		splay(y);
		rt = y;
		return siz[rc[y]];
	}
}
int sgtCountGreater(int now, int l, int r, int ll, int rr, int val) {
	if (ll <= l && r <= rr) return CountGreater(root[now], val);
	int mid = (l + r) >> 1, ret = 0;
	if (ll <= mid) ret = sgtCountGreater(now << 1, l, mid, ll, rr, val);
	if (rr > mid) ret += sgtCountGreater(now << 1 | 1, mid+1, r, ll, rr, val);
	return ret;
}
int L[N], R[N], Orz;
inline int MagHSK(int val) {
	int ret = 0;
	for (int i = 1; i <= Orz; ++i)
		ret += sgtCountGreater(1, 1, n, L[i], R[i], val);
	return ret;
}
inline int lca(int u, int v) {
	Orz = 0;
	while (top[u] != top[v]) {
		if (dep[top[u]] < dep[top[v]]) swap(u, v);
		L[++Orz] = dfn[top[u]];
		R[Orz] = dfn[u];
		u = fat[top[u]];
	}
	if (dep[u] < dep[v]) swap(u, v);
	L[++Orz] = dfn[v];
	R[Orz] = dfn[u];
	return v;
}
inline void Query(int x, int y, int k) {
	int acl = lca(x, y);
	if (dep[x] + dep[y] - dep[acl] - dep[acl] + 1 < k) {
		puts("invalid request!");
		return;
	}
	int l = 1, r = 100000000, mid;
	while (l < r) {
		mid = (l + r + 1) >> 1;
		int tmp = MagHSK(mid);
		if (tmp < k) r = mid - 1;
		else l = mid;
	}
	putint(l);
}
void sgtChange(int now, int l, int r, int pos, int delval, int insval) {
	if (l == r) {
		val[root[now]] = insval;
		return;
	}
	Delete(root[now], delval);
	Insert(root[now], root[now], insval, 0);
	int mid = (l + r) >> 1;
	if (pos <= mid) sgtChange(now << 1, l, mid, pos, delval, insval);
	else sgtChange(now << 1 | 1, mid+1, r, pos, delval, insval);
}
int dfs1(int now, int father, int deep) {
	dep[now] = deep; hah[now] = 1; fat[now] = father;
	for (int i = h[now]; i; i = edge[i].next) {
		if (edge[i].to == father) continue;
		hah[now] += dfs1(edge[i].to, now, deep+1);
		if (hah[edge[i].to] > hah[son[now]])
			son[now] = edge[i].to;
	}
	return hah[now];
}
void dfs2(int now, int father, int tp) {
	top[now] = tp; dfn[now] = ++clo; A[clo] = T[now];
	if (son[now]) {
		dfs2(son[now], now, tp);
		for (int i = h[now]; i; i = edge[i].next) {
			if (edge[i].to == father || edge[i].to == son[now]) continue;
			dfs2(edge[i].to, now, edge[i].to);
		}
	}
}
void build(int now, int l, int r) {
	for (int i = l; i <= r; ++i) Insert(root[now], root[now], A[i], 0);
	if (l == r) return;
	int mid = (l + r) >> 1;
	build(now << 1, l, mid);
	build(now << 1 | 1, mid + 1, r);
}
int main() {
	n = getint(); q = getint();
	for (int i = 1; i <= n; ++i)
		T[i] = getint();
	for (int i = 1; i < n; ++i) {
		x = getint(); y = getint();
		ins(x, y); ins(y, x);
	}
	dfs1(1, 0, 1);
	dfs2(1, 0, 1);
	build(1, 1, n);
	for (int i = 1; i <= q; ++i) {
		k = getint(); x = getint(); y = getint();
		if (k) Query(x, y, k);
		else {
			sgtChange(1, 1, n, dfn[x], T[x], y);
			T[x] = y;
		}
	}
}