#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, int val, int pos) {
	if (st == dr) {
		b[nod] = val;
		return;
	}
	int mid = st + (dr - st) / 2;
	if (pos <= mid)
		actualizare(st, mid, nod * 2, val, pos);
	else
		actualizare(mid + 1, dr, nod * 2 + 1, val, pos);

	b[nod] = max(b[nod * 2], b[nod * 2 + 1]);
}

void interogare(int st, int dr, int nod) {
    if (x <= st && dr <= y) {
        maxim = max(maxim, b[nod]);
        return;
    }
    int mid = st + (dr-st)/2;
    if (mid >= x) interogare(st, mid, nod*2);
    if (mid < y) interogare(mid+1, dr, 2*nod+1);
}

int main()
{
	fin >> n >> m;
	for (int i = 1; i <= n; i++) {
        fin >> x;
        actualizare(1,n,1,x,i);
	}

	for (int i = 1; i <= m; i++) {
		fin >> tip >> x >> y;
		if (tip == 0) {
            maxim = MIN;
			interogare(1, n, 1);
			fout << maxim << "\n";
		}
		else
			actualizare(1, n, 1, y, x);
	}

	return 0;
}