#include <fstream>

#define NMax 100010

using namespace std;

ifstream f("arbint.in");
ofstream g("arbint.out");

int nE, queries, val[NMax], segTree[4*NMax];

int get_max(int a, int b)
{
	if (a > b)
		return a;
	return b;
}

void build_seg_tree(int node, int left, int right)
{
	if (left == right) {
		segTree[node] = val[left];
		return;
	}

	int mid = (left + right) / 2;
	build_seg_tree(2 * node, left, mid);
	build_seg_tree(2 * node + 1, mid + 1, right);

	segTree[node] = get_max(segTree[2 * node], segTree[2 * node + 1]);
}

void update_seg_tree(int node, int left, int right, int pos, int val)
{
	if (left == right) {
		segTree[node] = val;
		return;
	}

	int mid = (left + right) / 2;
	if (pos <= mid)
		update_seg_tree(2 * node, left, mid, pos, val);
	else
		update_seg_tree(2 * node + 1, mid + 1, right, pos, val);

	segTree[node] = get_max(segTree[2 * node], segTree[2 * node + 1]);
}

int query_tree(int node, int left, int right, int rangeLeft, int rangeRight)
{
	if (right < rangeLeft || left > rangeRight)
		return -1;

	if (rangeLeft <= left && right <= rangeRight)
		return segTree[node];

	int mid = (left + right) / 2;
	int maxLeft = query_tree(2 * node, left, mid, rangeLeft, rangeRight);
	int maxRight = query_tree(2 * node + 1, mid + 1, right, rangeLeft, rangeRight);

	return get_max(maxLeft, maxRight);
}

int main()
{
	f >> nE >> queries;
	for (int i = 1; i <= nE; i++)
		f >> val[i];
	build_seg_tree(1, 1, nE);

	int cmd, a, b;
	for (int i = 1; i <= queries; i++) {
		f >> cmd >> a >> b;
		if (cmd == 1)
			update_seg_tree(1, 1, nE, a, b);
		else {
			int q =  query_tree(1, 1, nE, a, b);
			g << q << '\n';
		}
	}

	return 0;
}