/*
_ _ ___ ___ _ __ __
__| | __ _ / | / _ \ / _ \ (_)/ / _ \ \
/ _` | / _` | | | | | | | | | | | / / (_) | |
| (_| | | (_| | | | | |_| | | |_| | / /_ _ | |
\__,_| \__,_| |_| \___/ \___/ /_/(_) (_) | |
/_/
*/
//#include <iostream>
#include <queue>
#include <stack>
#include <map>
#include <cstdio>
#include <cmath>
#include <cstring>
#include <set>
#include <algorithm>
#include <bitset>
#include <time.h>
#include <tuple>
#include <fstream>
#include <iomanip>
#include <utility>
#include <ext/pb_ds/assoc_container.hpp>
#pragma warning "da 100% din tine. :)"
#define nl '\n'
#define cnl cout << '\n';
#define pb(x) push_back(x)
#define all(v) v.begin(),v.end()
#define rall(v) v.rbegin(),v.rend()
#define ll long long
#define ull unsigned ll
#ifdef INFOARENA
#define ProblemName "arbint"
#endif
#define MCONCAT(A, B) A B
#ifdef ProblemName
#define InFile MCONCAT(ProblemName, ".in")
#define OuFile MCONCAT(ProblemName, ".out")
#else
#define InFile "a.in"
#define OuFile "a.out"
#endif
//using namespace __gnu_pbds;
using namespace std;
ifstream cin(InFile);
ofstream cout(OuFile);
//typedef tree<int, null_type, less<int>, rb_tree_tag, tree_order_statistics_node_update> indexed_set;
template<class v, class type>
void print(v Vector, type nr) {
for_each(all(Vector), [](type x) {
cout << x << ' ';
});
}
int n, q;
int tree[400001];
inline void update(int nod, int st, int dr, int pos, int val) {
if (st == dr)
tree[nod] = val;
else {
int mid = (st + dr) >> 1;
if (pos <= mid) update(2 * nod, st, mid, pos, val);
else update(2 * nod + 1, mid + 1, dr, pos, val);
tree[nod] = max(tree[2 * nod], tree[2 * nod + 1]);
}
}
inline void query(int nod, int st, int dr, int a, int b, int &mx) {
if (st >= a && dr <= b)
mx = max(mx, tree[nod]);
else {
int mid = (st + dr) >> 1;
if (a <= mid) query(2 * nod, st, mid, a, b, mx);
if (b > mid) query(2 * nod + 1, mid + 1, dr, a, b, mx);
}
}
int main() {
ios_base::sync_with_stdio(false);
clock_t tStart = clock();
int val;
cin >> n >> q;
for (int i = 0; i < n; ++i) {
cin >> val;
update(1, 1, n, i + 1, val);
}
int op, a, b, mx;
while (q--) {
cin >> op >> a >> b;
if (!op) {
mx = -2;
query(1, 1, n, a, b, mx);
cout << mx << nl;
} else update(1, 1, n, a, b);
}
printf("\nTime taken: %.2fs\n", (double) (clock() - tStart) / CLOCKS_PER_SEC);
}