#include <bits/stdc++.h>

using namespace std;
int n,m,x,l,a,b;
vector<int>line[25];
vector<pair<int,int> >intervals[25];
int mx(int lin,int ind)
{
    if(ind>line[lin].size())
        return 0;
    if(intervals[lin][ind].first>=a && intervals[lin][ind].second<=b)
        return line[lin][ind];
    if(intervals[lin][ind].first>=a && intervals[lin][ind].first<=b)
        return max(mx(lin-1,ind*2),mx(lin-1,ind*2+1));
    if(intervals[lin][ind].second>=a && intervals[lin][ind].second<=b)
        return max(mx(lin-1,ind*2),mx(lin-1,ind*2+1));
    if(intervals[lin][ind].first<=a && intervals[lin][ind].second>=b)
        return max(mx(lin-1,ind*2),mx(lin-1,ind*2+1));
    return 0;
}
void modify(int pos,int val)
{
    int aux=line[0][pos];
    line[0][pos]=val;
    int k=1;
    pos/=2;
    while(k<l && (line[k][pos]==aux || line[k][pos]<val))
    {
        if(pos*2+1<line[k-1].size())
            line[k][pos]=max(line[k-1][pos*2],line[k-1][pos*2+1]);
        else
            line[k][pos]=line[k-1][pos*2];
        k++;
        pos/=2;
    }
}
void solve()
{
    int q;
    for(int i=1;i<=m;i++)
    {
        scanf("%d%d%d",&q,&a,&b);
        if(q==0)
        {
            a--;
            b--;
            printf("%d\n",mx(l-1,0));
            continue;
        }
        modify(a-1,b);
    }
}
int main()
{
    freopen("arbint.in","r",stdin);
    freopen("arbint.out","w",stdout);
    scanf("%d %d",&n,&m);
    for(int i=1;i<=n;i++)
    {
        scanf("%d",&x);
        line[0].push_back(x);
        intervals[0].push_back({i-1,i-1});
    }
    int k=1;
    while(line[k-1].size()!=1)
    {
        int lenght=line[k-1].size();
        for(int i=0;i<lenght-1;i+=2)
        {
             line[k].push_back(max(line[k-1][i],line[k-1][i+1]));
             intervals[k].push_back({intervals[k-1][i].first,intervals[k-1][i+1].second});
        }
        if(lenght%2==1)
        {
             line[k].push_back(line[k-1][lenght-1]);
             intervals[k].push_back({intervals[k-1][lenght-1].first,intervals[k-1][lenght-1].second});
        }
        k++;
    }
    l=k;
    solve();
    return 0;
}