#include <fstream>
#define NM 100100
using namespace std;
ifstream cin("arbint.in");
ofstream cout("arbint.out");
int arb[NM*4], v[NM], pos, val, n, m,start,finish, maxi;
inline void update(int nod, int left, int right) ///
{
    if(left==right) {
        arb[nod]=val;
        return;
    }
    int mij=(left+right)/2;
    if(pos<=mij)
        update(2*nod, left, mij);
    else update(2*nod+1,mij+1,right);
    arb[nod]=max(arb[nod*2], arb[2*nod+1]);
}

inline void Query(int nod, int left, int right)
{
    if(start<=left && right<=finish)
    {
        maxi=max(maxi, arb[nod]);
        return ;
    }
    int mij=(left+right)/2;
    if(start<=mij)
        Query(2*nod, left,mij);
    if(mij<finish)
        Query(2*nod+1, mij+1,right);
}

int main()
{
    ///0 a b, max v[a...b]=?
    ///1 a b v[a]=b
    int a,b,x,op;
    cin>>n>>m;
    for(int i=1;i<=n;i++)
    {
        cin>>x;
        pos=i; val=x;
        update(1,1,n);
    }
    for(int i=1; i<=m; ++i)
    {
        cin>>op>>a>>b;
        if(op==0)
        {
            maxi=-1; start=a;
            finish=b;
            Query(1,1,n);
            cout<<maxi<<'\n';
        }
        else{
            pos=a; val=b;
            update(1,1,n);
        }
    }
    return 0;
}