#include <cstdio>
#define NMAX 300010
#define Max(a,b) ((a>b)?a:b)
int m, n, a[NMAX], maxim;

void adaugare(int nod, int st, int dr, int poz, int val)
{
    if(st == dr)
    {
        a[nod] = val;
        return;
    }
    int mijl = (st+dr)/2;
    if(poz <= mijl)
        adaugare(nod*2, st, mijl, poz, val);
    else
        adaugare(nod*2+1, mijl+1, dr, poz, val);
    a[nod] = Max(a[nod*2+1],a[nod*2]);
}

void maxim_interval(int poz, int st, int dr, int x, int y)
{
    if(x <= st && dr <= y)
    {
        maxim = Max(maxim, a[poz]);
        return;
    }
    int mijl = (st+dr)/2;
    if(x <= mijl)
        maxim_interval(2*poz, st, mijl, x, y);
    if(y > mijl)
        maxim_interval(2*poz+1, mijl+1, dr, x, y);
}
int main()
{
    freopen("arbint.in", "r", stdin);
    freopen("arbint.out", "w", stdout);
    scanf("%d %d", &n, &m);
    int cod, x, y;
    for(int i = 1; i <= n; i++)
    {
        scanf("%d", &x);
        adaugare(1,1,n,i,x); /// nr in 'heap', interval ,...
    }
    for(int i = 1; i <= m; i++)
    {
        scanf("%d %d %d", &cod, &x, &y);
        if(cod == 1)
            adaugare(1,1,n,x,y);
        else
        {
            maxim = -1;
            maxim_interval(1,1,n,x,y);
            printf("%d\n", maxim);
        }
    }
    return 0;
}