#include <fstream>
#include <algorithm>


int n, m, op_code, a, b;
int tree[200000];



void build() 
{ 
        for (int i = n - 1; i > 0; --i) 
                tree[i] = std::max(tree[i<<1], tree[i<<1|1]);
}



void modify(int position, int value)
 { 
        for (tree[position += n] = value; position > 1; position >>= 1)
              tree[position>>1] = std::max(tree[position] , tree[position^1]);
}


int query(int left, int right)
{ 

        int result = -1;
        for (left += n, right += n; left < right; left >>= 1, right >>= 1) 
        {
                if (left&1) result = std::max(result, tree[left++]);
                if (right&1) result = std::max(result, tree[--right]);
        }
        return result;
}


int main()
{

        std::ifstream fin("arbint.in");
        std::ofstream fout("arbint.out");


        fin>>n>>m;
        for (int i = 0; i < n; ++i) 
                fin>>tree[n+i];
        build();


        for (int i = 0; i < m; ++i)
        {
                fin>>op_code>>a>>b;
                if (op_code == 0)
                        fout<<query(a-1, b)<<"\n";
                else if (op_code == 1)
                        modify(a-1, b);
        }


        fin.close();
        fout.close();
        return 0;


}