#include <stdio.h>
#define N 100005

int m,n,q,a,b,i,k,x,sol;
int arb[4*N];

int max(int a,int b)
{
    if(a>b)
        return a;
    return b;
}
void urca(int nod)
{
    if(nod!=0)
    {
        arb[nod]=max(arb[nod*2],arb[nod*2+1]);
        urca(nod/2);
    }
}
void schimba(int st,int dr,int nod)
{
    if(st==dr)
    {
        arb[nod]=x;
        urca(nod/2);
        return;
    }

    int m=(st+dr)/2;

    if(k<=m)
        schimba(st,m,2*nod);
    else
        schimba(m+1,dr,2*nod+1);
}
void query(int st,int dr,int nod)
{
    if(st>=a && dr<=b)
    {
        sol=max(sol,arb[nod]);
        return;
    }
    int m=(st+dr)/2;//,sol=0;

    if(a<=m)
        //sol=max(sol,query(st,m,2*nod));
        query(st,m,2*nod);
    if(b>m)
        //sol=max(sol,query(m+1,dr,2*nod+1));
        query(m+1,dr,2*nod+1);
    //wreturn sol;
}
int main()
{
    FILE *f1,*f2;
    f1=fopen("arbint.in","r");
    f2=fopen("arbint.out","w");

    fscanf(f1,"%d%d",&n,&m);
    for(i=0;i<n;i++)
    {
        fscanf(f1,"%d",&x);
        k=i+1;
        schimba(1,n,1);
    }

    for(i=0;i<m;i++)
    {
        fscanf(f1,"%d%d%d",&q,&a,&b);
        if(q==0)
        {
            sol=0;
            query(1,n,1);
            fprintf(f2,"%d\n",sol);
        }
        else
        {
            k=a;
            x=b;
            schimba(1,n,1);
        }
    }

    return 0;
}