#include <fstream>
#include <vector>

using namespace std;

ifstream in ("arbint.in");
ofstream out ("arbint.out");

class maxSegmentTree{
    int *data;
    int size;
    int n;
    void createVal(int left,int right,int position,vector<int> & v){ // function used by a constructor
        if(left==right){ // current node hold the number from v with index left
            data[position]=v[left-1]; // this is cleary its maximum
            return;
        }
        createVal(left,(left+right)/2,2*position,v); // we explore the left interval,mid interval
        createVal((left+right)/2+1,right,2*position+1,v); // we explore the mid+1,right interval
        data[position]=max(data[2*position],data[2*position+1]); // we set the maximum on the current interval based on previous explorations
    }
    int getMax(int left,int right,int a,int b,int position){ // we will find the maximum in the [a,b]
        int result=-1;
        int mid=(left+right)/2;
        if(left>=a&&right<=b)
            return data[position];
        if(mid<b){
            result=max(result,getMax(mid+1,right,a,b,2*position+1));
        }
        if(mid>=a){
            result=max(result,getMax(left,mid,a,b,2*position));
        }
        return result;
    }
    bool updateVal(int left,int right,int position,int index,int val){
        int mid=(left+right)/2;
        if(left==right && left==index){
            data[position]=val;
            return true;
        }
        if(mid>=index){
            updateVal(left,mid,2*position,index,val);
        }
        else{
            updateVal(mid+1,right,2*position+1,index,val);
        }
        data[position]=max(data[2*position],data[2*position+1]);
    }
public:
    maxSegmentTree(int x){
        n=x;
        int log,aux;
        //for(aux=1;aux<=n;aux<<=1,log++);
        //log--;
        log=8;
        data=new int[n*log];
        for(int i=1;i<n*log;++i){
            data[i]=-1;
        }
    }
    maxSegmentTree(vector<int> & v){
        n=v.size();
        int log=8;
        data=new int[n*log];
        createVal(1,n,1,v);
    }
    int query(int l,int r){
        return getMax(1,n,l,r,1);
    }
    bool update(int position,int value){
        return updateVal(1,n,1,position,value);
    }
};

int main(){
    int n,m;
    maxSegmentTree *st;
    vector<int> v;
    in>>n>>m;
    int op,a,b;
    for(int i=1;i<=n;++i){
        in>>a;
        v.push_back(a);
    }
    st=new maxSegmentTree(v);
    for(int i=1;i<=m;++i){
        in>>op>>a>>b;
        if(op==0){
            out<<st->query(a,b)<<"\n";
            continue;
        }
        st->update(a,b);
    }
    return 0;
}