#include <fstream>
#include <vector>
#include <algorithm>
using namespace std;

ifstream f("arbint.in");
ofstream q("arbint.out");

void update(int node, int left, int right, vector<int>& arb, int position, int value)
{
   if (left == right)
   {
      arb[node] = value;
      return;
   }
   int mid = (left + right) / 2;
   if (position > mid) update(2 * node + 1, mid + 1, right, arb, position, value);
   else update(2 * node, left, mid, arb, position, value);
   arb[node] = max(arb[2 * node], arb[2 * node + 1]);
}

int query(int node, int start, int end, vector<int>&arb, int left, int right)
{
   if (left <= start && end <= right)
   {
      return arb[node];
   }
   int mid = (start + end) / 2, maxSt = -1, maxDr = -1;
   if (left <= mid)
      maxSt = query(node * 2, start, mid, arb, left, right);
   if (mid < right)
      maxDr = query(node * 2 + 1, mid + 1, end, arb, left, right);
   return max(maxSt, maxDr);
}

int main()
{
   int M, N, x, op, a, b;
   
   f >> N >> M;
   vector<int> maxArb(N * 4, -1);

   for(int i = 1; i <= N; ++i)
   {
      f >> x;
      update(1, 1, N, maxArb, i, x);
   }

   for(;M--;)
   {
      f >> op >> a >> b;
      if (op == 1) update(1, 1, N, maxArb, a, b);
      else q << query(1, 1, N, maxArb, a, b) << "\n";
   }



   f.close();
   q.close();
   return 0;
}