/// maximul dintr-o ferestra cu m operatii de tipul
/// 1 -> v[poz] = val;
/// 2 -> care este valoarea maxima din intervalul pozitiilor x y

#include <iostream>
#include <fstream>

using namespace std;
const int N = 1e5;
const int INF = 2e9;

int v[N], seg_tree[2*N];

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

void recalculate ( int node ) {
   seg_tree[node] = max ( seg_tree[2*node+1], seg_tree[2*node+2] );
}

void build ( int node, int l, int r ) {

    if ( l == r )
      seg_tree[node] = v[l];
    else {
      int mid = l + ( r - l ) / 2;
      build ( 2 * node + 1, l, mid );
      build ( 2 * node + 2, mid + 1, r );
      recalculate ( node );
    }
}

void update ( int node, int l, int r, int poz, int val ) {

    if ( l == r )
      seg_tree[node] = val;
    else {
      int mid = l + ( r - l ) / 2;
      if ( poz <= mid )
        update ( 2 * node + 1, l, mid, poz, val );
      else
        update ( 2 * node + 2, mid + 1, r, poz, val );
      recalculate ( node );
    }
}

int query ( int node, int l, int r, int x, int y ) {

   if ( x <= l && r <= y )
     return seg_tree[node];
   else {

     int ans = -INF;
     int mid = l + ( r - l ) / 2;

     if ( x <= mid )
       ans = max ( ans, query ( 2 * node + 1, l, mid, x, y ) );
     if ( y >= mid + 1 )
       ans = max ( ans, query ( 2 * node + 2, mid + 1, r, x, y ) );
     return ans;
   }
}

int main()
{
   int n, m;
   int tip, poz, val, x, y;

   fin >> n >> m;
   for ( int i = 1; i <= n; i ++ )
      fin >> v[i];
   build ( 0, 1, n );

   for ( int i = 1; i <= m; i ++ ) {

      fin >> tip;
      if ( tip == 1 ) {
        fin >> poz >> val;
        update ( 0, 1, n, poz, val );
      }
      else {
        fin >> x >> y;
        fout << query ( 0, 1, n, x, y );
        fout << '\n';
      }
   }


    return 0;
}