#include <fstream>
using namespace std; 

ifstream fin("arbint.in");
ofstream fout("arbint.out"); 

int noduri[4000001], valori[1000001];

void valoareNod(int nod, int st, int dr)
{
    if (st == dr)
    {
        noduri[nod] = valori[st]; 
        return; 
    }
    valoareNod(nod * 2, st, (st + dr) / 2); 
    valoareNod(nod * 2 + 1, (st + dr) / 2 + 1, dr); 
    noduri[nod] = max(noduri[2 * nod], noduri[2 * nod + 1]);
}

void modificareNod(int indiceNod, int st, int dr, int valInitiala, int valNoua)
{
    if (valInitiala < st || valInitiala > dr) return; 
    if (st == dr)
    {
        noduri[indiceNod] = valNoua; 
        return;
    }

    modificareNod(indiceNod * 2, st, (st + dr) / 2, valInitiala, valNoua); 
    modificareNod(indiceNod * 2 + 1, (st + dr) / 2 + 1, dr, valInitiala, valNoua); 
    noduri[indiceNod] = max(noduri[indiceNod * 2], noduri[indiceNod * 2 + 1]); 

}

int valMaxima(int indiceNod, int st, int dr, int val1, int val2)
{
    if (val2 < st || dr < val1) return 0;
    if (val1 <= st &&  dr <= val2) return noduri[indiceNod]; 
    return max(valMaxima(2 * indiceNod, st, (st + dr) / 2, val1, val2), 
        valMaxima(2 * indiceNod + 1, (st + dr) / 2 + 1, dr, val1, val2)); 
}

int main()
{
    int nrElemente, nrOperatii; 
    fin >> nrElemente >> nrOperatii; 

    for (int i = 1; i <= nrElemente; i++)
        fin >> valori[i]; 
    valoareNod(1, 1, nrElemente); 

    for (int i = 1; i <= nrOperatii; i++)
    {
        int operatie; fin >> operatie; 
        int a, b; fin >> a >> b;
        switch (operatie)
        {
        case 0: 
            fout << valMaxima(1, 1, nrElemente, a, b) << '\n';
            break;
        case 1: 
            modificareNod(1, 1, nrElemente, a, b); 
            break;
        }
    }
}