#include <iostream>
#include <cstdio>
using namespace std;
const int MAXN = 100000;

int segTree[4*MAXN+1], N, M;

void update(int nod, int left, int right, int poz, int value)
{
    if( left == right )
        segTree[ nod ] = value;
    else
    {
        int m = (left + right)/2;

        if( poz <= m )
            update(2*nod,left,m,poz,value);
        else update(2*nod+1,m+1,right,poz,value);

        segTree[ nod ] = max( segTree[ 2*nod ], segTree[ 2*nod + 1 ] );
    }
}

int maxim = -1;

void querry(int nod, int left, int right, int a, int b)
{
    if( a <= left && right <= b )
        maxim = max( maxim, segTree[ nod ] );
    else
    {
        int m = (left + right)/2;

        if( a <= m )
            querry(2*nod,left,m,a,b);
        if( m < b )
            querry(2*nod+1,m+1,right,a,b);
    }
}

void citire()
{
    scanf("%d %d",&N, &M);
    for(int i = 1; i <= N; i++)
    {
        int x; scanf("%d",&x);
        update(1,1,N,i,x);
    }
}

int main()
{
    freopen("arbint.in","r",stdin);
    freopen("arbint.out","w",stdout);

    citire();

    for(int i = 1; i <= M; i++)
    {
        int cod, a, b; scanf("%d %d %d",&cod,&a,&b);

        if( cod == 0 )
        {
            maxim = -1;
            querry(1, 1, N, a, b);
            printf("%d\n",maxim);
        }
        else update(1, 1, N, a, b);
    }

    return 0;
}