#include <iostream>
#include <fstream>

const int NMAX = 1e5;

int n;

int a[1 + NMAX];

int segTree[3 * NMAX];

void build(int node, int left, int right) {
  if (left == right) {
    segTree[node] = a[left];
    return;
  }

  int mid      = (left + right) / 2;
  int leftSon  = 2 * node;
  int rightSon = 2 * node + 1;

  build(leftSon, left, mid);
  build(rightSon, mid + 1, right);

  segTree[node] = std::max(segTree[leftSon], segTree[rightSon]);
}

void update (int node, int left, int right, int ind, int val) {
  if (left == right) {
    segTree[node] = val;
    return;
  }

  int mid      = (left + right) / 2;
  int leftSon  = node * 2;
  int rightSon = node * 2 + 1;

  if (ind <= mid)
    update(leftSon, left, mid, ind, val);
  else
    update(rightSon, mid + 1, right, ind, val);

  segTree[node] = std::max(segTree[leftSon], segTree[rightSon]);
}

int query(int node, int left, int right, int qLeft, int qRight) {
  if (qLeft <= left && right <= qRight)
    return segTree[node];

  int mid      = (left + right) / 2;
  int leftSon  = 2 * node;
  int rightSon = 2 * node + 1;
  int ans = -1;

  if (qLeft <= mid)
    ans = std::max(ans, query(leftSon, left, mid, qLeft, qRight));
  if (mid + 1 <= qRight)
    ans = std::max(ans, query(rightSon, mid + 1, right, qLeft, qRight));

  return ans;
}

int main() {
  std::ifstream in("arbint.in");
  std::ofstream out("arbint.out");

  int m;

  in >> n >> m;

  for (int i = 1; i <= n; ++i)
    in >> a[i];

  build(1, 1, n);

  for (int i = 1; i <= m; ++i) {
    int op, a, b;

    in >> op >> a >> b;

    if (op == 1)
      update(1, 1, n, a, b);
    else
      out << query(1, 1, n, a, b) << '\n';
  }

  return 0;
}