#include<iostream>
#include<vector>
#include<cstdio>
#define ERR -2018
#define INT_MIN -1.e+9
using namespace std;

class SegNode{
    public:

    int l,u;//lower and upper limit
    SegNode* left;
    SegNode* right;
    int val;

    SegNode(int L , int U , vector<int>* arr) {
        if(L<=U){
        l = L;
        u = U;
        if(u==l){
            val = (*arr)[u];
            left = right = 0;
        }
        else{
            int h = (l+u)/2;
            left = new SegNode(l , h, arr);
            right = new SegNode(h+1 , u, arr);
            val = max(left->val , right->val);
        }
        }
    }

    //return true if [x,y] overlaps [l,u]
    bool overlaps(int x,int y){
        int a=l , b=u;
        return ((a<=x) && (x<=b)) || ((a<=y) && (y<=b)) ||
               ((x<=a) && (a<=y)) || ((x<=b) && (b<=y));
    }


    int search_max(int a, int b)//get maximum value between indexes a and b
    {
        //if((a<0) || (b>N) || (a>b)) return ERR;
        if(!this->overlaps(a,b))
            return INT_MIN;
        if(a<=l && u<=b) //if [l,u] included in [a,b]
            return val;
        return max(left->search_max(a,b) , right->search_max(a,b));
    }

    void update_value(int k,int v)//arr[k]=v
    {
        if(l==u){
            if(l==k) val = v;
            return;
        }
        //else
        int h = (l+u)/2;
        if(k<=h)
            left->update_value(k,v);
        else
            right->update_value(k,v);
        val = max(left->val , right->val);
    }

    void destroy()
    {
        if(left) left->destroy();
        delete left;
        if(right) right->destroy();
        delete right;
    }

    void print()
    {
        printf("[%d,%d] ",l,u);
        if(left) (*left).print();
        if(right) (*right).print();
    }
};

class SegTree{
    SegNode* root;
    int N;//interval size

    public:

    SegTree(vector<int>* arr)
    {
        N = arr->size()-1;
        root = new SegNode(0,N,arr);
    }

    void update_value(int k,int v)//arr[k]=v
    {
        root->update_value(k,v);
    }

    int search_max(int a, int b)//get maximum value between indexes a and b
    {
        if((a<0) || (b>N) || (a>b)) return ERR;
        return root->search_max(a,b);
    }
    void print()
    {
        root->print();
    }

    void destroy(){
        root->destroy();
    }

};

int main()
{
    freopen("arbint.in","r",stdin);
    freopen("arbint.out","w",stdout);
    int N,M;
    cin>>N>>M;
    vector<int> arr(N);
    for(int i=0;i<N;i++)
        cin>>arr[i];
    SegTree tree(&arr);
    int op,a,b;
    while(M--){
        cin>>op>>a>>b;
        a--;b--;
        if(op) //update
            tree.update_value(a,b);
        else //get max
            cout<<tree.search_max(a,b)<<"\n";
    }
    return 0;
}