/*
ID: gabriel100
LANG: C++
TASK:
*/
#include <cstdio>
#include <algorithm>
//#include <time.h>
#include <queue>
#include <cmath>
#include <stack>
#include <fstream>
#include <bitset>
#include <set>

#define nl '\n'
#define F first
#define S second
#define all(v) v.begin(),v.end()
#define eb(x) emplace_back(x)
#define ull unsigned long long
#define ll long long
#define ProblemName "arbint"
#define LocalName "data"
#ifdef INFOARENA
#define Filename ProblemName
#else
#define Filename LocalName
#endif
#define Input Filename".in"
#define Output Filename".out"
using namespace std;
ifstream cin(Input);
ofstream cout(Output);

template<class a, class type>
void print(a v, type t) {
    for_each(all(v), [](type x) { cout << x.first << ' '; });
    cout << nl;
}

#define N 100000

int v[N * 2+ 'S'+'T'+'E'+'F'+'F'+'Y'];

int n, q, a, b;
int cod;

void update(int nod,int st,int dr,int pos,int val){
    if(st == dr){
        v[nod] = val;
    } else {
        int mij = (st+dr)  >> 1;
        if(pos <= mij) update(2*nod,st,mij,pos,val);
        else update(2*nod+1,mij+1,dr,pos,val);
        v[nod] = max(v[2*nod],v[2*nod+1]); // cand ne intoarcem
    }
}
int mx;
void GetMax(int nod,int st,int dr,int a, int b){
    if(st >= a && dr <= b){
        mx = max(mx,v[nod]);
    } else {
        int mij = (st+dr) >> 1;
        if(a<=mij) GetMax(2*nod,st,mij,a,b);
        if(b>mij) GetMax(2*nod+1,mij+1,dr,a,b);
    }
}
int main() {
    //    clock_t tStart = clock();
    ios_base::sync_with_stdio(false);
    cin >> n >> q;
    for (int i = 1; i <= n; ++i) {
        cin >> a;
        update(1, 1, n, i, a);
    }

    while (q--) {
        cin >> cod >> a >> b;
        if (!cod) {
            mx = -1;
            GetMax(1, 1, n, a, b);
            cout << mx << nl;
        } else {
            update(1, 1, n, a, b);
        }

    }
    //    printf("\nTime taken: %.2fs\n", (double) (clock() - tStart) / CLOCKS_PER_SEC);
    cout.close();
}