#include <bits/stdc++.h>

using namespace std;
ifstream f("arbint.in");
ofstream g("arbint.out");

const int N=1<<18;
int n,m,p,A[N];
void buildAint()
{
    for(int i=1;i<=n;i++)
        f>>A[i+p-1];
    for(int i=p-1;i>=1;i--)
        A[i]=max(A[2*i],A[2*i+1]);
}
int getMax(int nod,int sa,int da,int sq,int dq)
{
    /// [sa,da] disjunct de [sq,dq] - returnez 0
    if(sa>dq||sq>da)
        return 0;
    /// [sa,da] inclus [sq,dq] - returnez A[nod]
    if(sq<=sa&&da<=dq)
        return A[nod];
    /// altfel - iau max din prima si adoua jumatate
    /// returnez maximul intre cele doua valori
    int fiuSt=2*nod;
    int fiuDr=2*nod+1;
    int mi=(sa+da)/2;
    return max(getMax(fiuSt,sa,mi,sq,dq),getMax(fiuDr,mi+1,da,sq,dq));
}
void update(int nod,int val)
{
    nod=nod+p-1;
    A[nod]=val;
    nod/=2;/// incep din "tatal" nodului modificat
    while(nod>0)
    {
        int fiuSt=2*nod;
        int fiuDr=2*nod+1;
        A[nod]=max(A[fiuSt],A[fiuDr]);///recalculez valoarea
        nod/=2;///merg la tata
    }
}
int main()
{
    f>>n>>m;
    p=1;
    while(p<n)p*=2;
    buildAint();
    for(;m;m--)
    {
        int tip,a,b;
        f>>tip>>a>>b;
        if(tip==0)
            g<<getMax(1,1,p,a,b)<<'\n';
        else
            update(a,b);
    }
    return 0;
}

//5 5
//4 3 5 6 1
//0 1 3
//1 3 2
//0 2 3
//1 4 2
//0 1 5
//                                    <0>
//                                 8< 1>
//                                 [1,8]
//               8< 2>                                1< 3>
//               [1,4]                                [5,8]
//       4< 4>             8< 5>              1< 6>            0< 7>
//       [1,2]             [3,4]              [5,6]            [7,8]
//  4< 8>     3< 9>   2<10>     8<11>    1<12>     0<13>   0<14>    0<15>
//  [1,1]     [2,2]   [3,3]     [4,4]    [5,5]     [6,6]   [7,7]    [8,8]
//n<=2^k=P+P/2+P/4 ... +1
//
//suma(2^i) i=1..k
//5->8->16
//suport daca n<=2^k am nevoie de 2^(k+1)pozitii
//100000<=2^17->2^18