#include <fstream>
#include <iostream>

using namespace std;

struct nod {
    int max;
    nod* stanga;
    nod* dreapta;
};

nod* buildArbore(nod* root, int* v, int a, int b){

    root = new nod;

    if(b-a == 1){
        root->stanga = buildArbore(root->stanga, v, a, a);
        root->dreapta = buildArbore(root->dreapta, v, b, b);
    }
    else if (a != b) {
        root->stanga = buildArbore(root->stanga, v, a, (b+a)/2);
        root->dreapta = buildArbore(root->dreapta, v, (b+a)/2 + 1, b);
    }

    if(a == b){
        root->max = v[a];
        root->stanga = NULL;
        root->dreapta = NULL;
    }
    else
        root->max = root->stanga->max > root->dreapta->max ? root->stanga->max : root->dreapta->max;

    return root;
}

void rebuildArbore(nod* root, int idx, int newValue, int begin, int end){

    if(!root->stanga && !root->dreapta){
        root->max = newValue;
        return ;
    }

    if(idx <= (begin+end)/2 || idx == begin)
        rebuildArbore(root->stanga, idx, newValue, begin, (begin+end)/2);
    else if(idx > (begin+end)/2 || idx == end)
        rebuildArbore(root->dreapta, idx, newValue, (begin+end)/2 + 1, end);

    root->max = root->stanga->max > root->dreapta->max ? root->stanga->max : root->dreapta->max;
}

int maxInt(nod* root, int a, int b, int currentMax, int begin, int end){

    if(begin >= a && end <= b)
        return root->max;

    int maxSt = -1, maxDr = -1;

    if(a <= (begin+end)/2)
        maxSt = maxInt(root->stanga, a, (begin+end)/2 >= b ? b : (begin+end)/2, currentMax, begin, (begin+end)/2);

    if(b > (begin+end)/2)
        maxDr = maxInt(root->dreapta, a >= (begin+end)/2 + 1 ? a : (begin+end)/2 + 1, b, currentMax, (begin+end)/2+1, end);

    return maxSt > maxDr ? maxSt : maxDr;
}

int main(){

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

    fstream::sync_with_stdio(false);

    int M,N;
    fin>>N>>M;

    int* v = new int[N];

    for(int i = 0; i < N; i++)
        fin>>v[i];

    nod* root;

    root = buildArbore(root, v, 0, N-1);

    int op,a,b,max;

    for(int i = 0; i < M; i++){
        fin>>op>>a>>b;
        if(!op)
            fout<<maxInt(root, a-1, b-1, -1, 0, N-1)<<"\n";
        else rebuildArbore(root, a-1, b, 0, N-1);
    }

    return 0;
}