#include<cstdio>
#include<vector>
#define max(a,b) a>b ? a : b
using namespace std;
FILE *in = fopen("arbint.in", "r"), *out = fopen("arbint.out", "w");

int n, m, valMax;
int arb[400001];

void Update(int nod, int st, int dr, int poz, int val){
	if (st == dr) {arb[nod] = val; return;}
	int mij = (st + dr) / 2;
	if (poz <= mij) Update(2*nod, st, mij, poz, val);
	else Update(2*nod + 1, mij + 1, dr, poz, val);
	arb[nod] = max(arb[2*nod], arb[2*nod+1]);
}

void Query(int nod, int st, int dr, int &first, int &last){
	if (first <= st && dr <= last){
		if (valMax < arb[nod]) valMax = arb[nod]; 
		return;
	}
	int mij = (st + dr) / 2;
	if (first <= mij) Query(nod * 2, st, mij, first, last);
	if (mij < last) Query(nod * 2 + 1, mij + 1, dr, first, last);
}

int main(){
	fscanf (in, "%d %d", &n, &m);
	int i, tip, a, b;
	for (i = 1; i <= n; i++) {
		fscanf(in, "%d", &a);
		Update(1, 1, n, i, a);
	}
	
	for (i = 0; i < m; i++){
		fscanf(in, "%d %d %d", &tip, &a, &b);
		if (tip == 1){
			Update(1, 1, n, a, b);
		}
		else {
			valMax = -1;
			Query(1, 1, n, a, b);
			fprintf (out, "%d\n", valMax);
		}
	}
	
	return 0;
}