#include <fstream>
#include <vector>
#include <bitset>
#include <queue>
#include <algorithm>
#include <utility>
#include <cstring>
#include <string>
#include <stack>
#include <deque>
#include <iomanip>
#include <set>
#include <map>
#include <cassert>
#include <ctime>
#include <list>
#include <iomanip>

using namespace std;

string file = "arbint";

ifstream cin( (file + ".in").c_str() );
ofstream cout( (file + ".out").c_str() );

const int MAXN = 100005;
const int oo = (1<<31)-1;

typedef vector<int> Graph[MAXN];
typedef vector<int> :: iterator It;

const inline int min(const int &a, const int &b) { if( a > b ) return b;   return a; }
const inline int max(const int &a, const int &b) { if( a < b ) return b;   return a; }
const inline void Get_min(int &a, const int b)    { if( a > b ) a = b; }
const inline void Get_max(int &a, const int b)    { if( a < b ) a = b; }

struct ClassComp {
    inline bool operator () (const int &a, const int &b) const {
        return a > b;
    }
};

int N, M, A[4 * MAXN], Sol;

inline void Add(int node, int st, int dr, int pos, int val) {
    if(st == dr) {
        A[node] = val;
        return;
    }
    int mid = ((st + dr) >> 1);
    if(pos <= mid)
        Add(2*node, st, mid, pos, val);
    else Add(2*node + 1, mid+1, dr, pos, val);
    A[node] = max(A[2*node], A[2*node + 1]);
}

inline void Query(int node, int st, int dr, int a, int b) {
    if(a <= st && dr <= b) { /// inclus
        Sol = max(Sol, A[node]);
        return;
    }
    int mid = (st + dr) >> 1;
    if(a <= mid) {
        Query(2*node, st, mid, a, b);
    }
    if(mid < b)
        Query(2*node+ 1, mid + 1, dr, a, b);
}

int main() {
    cin >> N >> M;
    for(int i = 1 ; i <= N ; ++ i) {
        int x;
        cin >> x;
        Add(1, 1, N, i, x);
    }
    for(int i = 1 ; i <= M ; ++ i) {
        bool op;
        cin >> op;
        if(op) {
            int x, y;
            cin >> x >> y;
            Add(1, 1, N, x, y);
        }
        else {
            Sol = -1;
            int x, y;
            cin >> x >> y;
            Query(1, 1, N, x, y);
            cout << Sol << '\n';
        }
    }
    cin.close();
    cout.close();
    return 0;
}