#include <fstream>
#include <cstdlib>

using namespace std;

const int N_MAX=262144;

int v[N_MAX];

inline int _max(int x, int y) {return x >= y ? x : y;}
inline void Update(int vertex, int left, int right, const int& xIndex, const int& xValue)
{
    if(left == right)
        v[vertex]=xValue;
    else {
            int middle=(left+right)>>1;
            if(xIndex <= middle)
                Update(vertex<<1, left, middle, xIndex, xValue);
            else Update((vertex<<1)|1, middle+1, right, xIndex, xValue);
            v[vertex]=_max(v[vertex<<1], v[(vertex<<1)|1]);
         }
}
inline int Query(int vertex, int left, int right, const int& start, const int& end)
{
    if(left >= start && right <= end)
        return v[vertex];
    else {
            int middle=(left+right)>>1, m1=-1, m2=-1;
            if(start <= middle)
                m1=Query(vertex<<1, left, middle, start, end);
            if(middle < end)
                m2=Query((vertex<<1)|1, middle+1, right, start, end);
            return _max(m1, m2);
         }
}
int main()
{
    int N, M, i, x, op, a, b;
    ifstream in("arbint.in");
    ofstream out("arbint.out");

    in>>N>>M;
    for(i=1; i <= N; ++i)
    {
        in>>x;
        Update(1, 1, N, i, x);
    }
    for(; M; --M)
    {
        in>>op>>a>>b;
        if(0 == op)
            out<<Query(1, 1, N, a, b)<<"\n";
        else Update(1, 1, N, a, b);
    }

    return EXIT_SUCCESS;
}