#include <fstream>
#define NMax 1000000

using namespace std;
ifstream fin("arbint.in");
ofstream fout("arbint.out");
int n, m, a[NMax], b[NMax], tip, x, y, maxim;
const int MIN = -1;
int max(int a, int b) {
	if (a > b)
		return a;
	else
		return b;
}
void actualizare(int st, int dr, int nod) {
	if (st == dr) {
		b[nod] = y;
		return;
	}
	int mid = st + (dr - st) / 2;
	if (x <= mid)
		actualizare(st, mid, nod * 2);
	else
		actualizare(mid + 1, dr, nod * 2 + 1);

	b[nod] = max(b[nod * 2], b[nod * 2 + 1]);
}
int interogare(int st, int dr, int nod) {
	if (dr < x || st > y)
		return MIN;
	else if (st >= x && dr <= y)
		return b[nod];
	else {
		int mid = st + (dr - st) / 2;
		maxim = max(interogare(st, mid, nod * 2), interogare(mid + 1, dr, 2 * nod + 1));
		return maxim;
	}
}
void arbore(int st, int dr, int nod) {
	if (st == dr) {
		b[nod] = a[st];
	}
	else {
		int mid = st + (dr - st) / 2;
		arbore(st, mid, 2 * nod);
		arbore(mid + 1, dr, 2 * nod + 1);
		b[nod] = max(b[nod * 2], b[nod * 2 + 1]);
	}
}
int main()
{
	fin >> n >> m;
	for (int i = 1; i <= n; i++)
		fin >> a[i];
	arbore(1, n, 1);
	for (int i = 1; i <= m; i++) {
		fin >> tip >> x >> y;
		if (tip == 0) {
			interogare(1, n, 1);
			fout << maxim << "\n";
		}
		else
			actualizare(1, n, 1);
	}
	return 0;
}