#include<iostream>
#include<cstdio>

using namespace std;

int x, pos, maxi=-1, si, sf, maxim[400000], n, m;
void Inserare(int nod, int left, int right)
{
        if(left==right)
            maxim[nod]=x;
        else
        {
            int mij=(left+right)/2;
            if(pos<=mij)
                Inserare(2*nod, left, mij);
            else
                Inserare(2*nod+1, mij+1, right);
            maxim[nod]=max(maxim[2*nod], maxim[2*nod+1]);
        }
}
void Interogare(int nod, int left, int right)
{
    if(si<=left && right<=sf)
        {if(maxim[nod]>maxi)
            {maxi=maxim[nod];}}
    else
    {
        int mij=(left+right)/2;
        if(si<=mij)
            Interogare(2*nod, left, mij);
        if(mij+1<=sf)
            Interogare(2*nod+1, mij+1, right);
    }
}
int main()
{
    FILE *fin, *fout;
    fin=fopen("arbint.in","r");
    fout=fopen("arbint.out","w");

    int  i, y, a, b;
    fscanf(fin, "%d %d", &n, &m);
    for(i=1; i<=n; i++)
    {
        fscanf(fin, "%d", &x);
        pos=i;
        Inserare(1,1,n);
    }
    for(i=0; i<m; i++)
    {
        fscanf(fin, "%d %d %d", &y, &a, &b);
        if(y==0)
        {
            maxi=-2;
            si=a;
            sf=b;
            Interogare(1,1,n);
            fprintf(fout, "%d\n",maxi);
        }
        if(y==1)
        {
            pos=a;
            x=b;
            Inserare(1,1,n);
        }
    }
}