#include <iostream>
#include <fstream>

using namespace std;

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

int n,m,val,tree[400010],type,a,b,maxim;

void update(int node, int left, int right, int pos, int val)
{
    if(left==right)
    {
        tree[node]=val;
        return;
    }
    int mid=(left+right)/2;
    if(pos<=mid)
        update(2*node,left,mid,pos,val);
    else
        update(2*node+1,mid+1,right,pos,val);
    tree[node]=max(tree[2*node],tree[2*node+1]);
}

void query(int node, int left, int right, int st, int dr)
{
    if(st<=left && right<=dr)
    {
        if(maxim<tree[node])
            maxim=tree[node];
        return;
    }
    int mid=(left+right)/2;
    if(st<=mid)
        query(2*node,left,mid,st,dr);
    if(mid<dr)
        query(2*node+1,mid+1,right,st,dr);
}

int main()
{
    fin >> n >> m;
    for(int i=1;i<=n;i++)
    {
        fin >> val;
        update(1,1,n,i,val);
    }
    for(;m;--m)
    {
        fin >> type >> a >> b;
        if(type==0)
        {
            maxim=-1;
            query(1,1,n,a,b);
            fout << maxim << '\n';
        }
        else
            update(1,1,n,a,b);
    }
    return 0;
}