#include <stdio.h>
#include <math.h>
#include <algorithm>
using namespace std;

#define UPDATE 1
#define QUERY 0

#define MAX_N 100000
const int SQ_N = 1024;
const int BATOG_SIZE = (MAX_N + SQ_N - 1) / SQ_N;

int v[MAX_N];
int vLength;

int batog[BATOG_SIZE];

void build() {
  int i;

  for (i = 0; i < vLength; ++i)
    batog[i / SQ_N] = max(batog[i / SQ_N], v[i]);
}

inline void update(int pos, int value) {
  int left, right;

  v[pos] = value;
  left = pos / SQ_N * SQ_N;
  right = left + SQ_N;

  batog[pos / SQ_N] = 0;
  while (left < right)
    batog[pos / SQ_N] = max(batog[pos / SQ_N], v[left++]);
}

int query(int left, int right) {
  int firstInterval, lastInterval, result;

  firstInterval = (left + SQ_N - 1) / SQ_N * SQ_N;
  lastInterval = right / SQ_N * SQ_N;

  result = 0;
  while (left <= right && left < firstInterval)
    result = max(result, v[left++]);
  while (right >= left && right >= lastInterval)
    result = max(result, v[right--]);

  firstInterval /= SQ_N;
  lastInterval /= SQ_N;

  while (firstInterval < lastInterval)
    result = max(result, batog[firstInterval++]);

  return result;
}

int main() {
  FILE *fin, *fout;
  fin = fopen("arbint.in", "r");
  fout = fopen("arbint.out", "w");

  int i, q, op, a, b;

  fscanf(fin, "%d%d", &vLength, &q);
  for (i = 0; i < vLength; ++i)
    fscanf(fin, "%d", &v[i]);

  build();

  while (q--) {
    fscanf(fin, "%d%d%d", &op, &a, &b);

    if (op == UPDATE)
      update(a - 1, b);
    else if (op == QUERY)
      fprintf(fout, "%d\n", query(a - 1, b - 1));
  }

  fclose(fin);
  fclose(fout);
  return 0;
}