#include <stdlib.h>
#include <cstdio>
#include <algorithm>

using namespace std;

int aib[100001];
int vec[100001];
int n,m,nr,o,a,b;

#define ZERO(x) ( (x) & (-x) )
#define INF (0x3f3f3f3f)


inline int query(int a,int b) {
    int vmax = -INF;
    if(a>b) return -INF;

    for(int i = b ; i >= a ; )
        if(i - ZERO(i) + 1 >= a ) // acest +1 face diferenta de la 70p la 100p :d
            vmax = max( vmax , aib[i]) , i -= ZERO(i);
        else
            vmax = max( vmax , vec[i]) , i--;

    return vmax;
}

inline void update(int p,int nr) {

    vec[p] = nr;

    aib[p] = max( query(p - ZERO(p) + 1 , p - 1 ) , vec[p] );

    for(int i = p + ZERO(p) ; i <= n ; i += ZERO(i) )
        aib[i] = max (vec[p] , max( query(p + 1 , i ) , query( i - ZERO(i) + 1  , p - 1 ) ) );

}

inline void construct(int p, int nr) {

    vec[p] = nr;

    aib[p] = max( aib[p] , max( query(p - ZERO(p) + 1 , p - 1 ) , vec[p] ) );

    if( p + ZERO(p) <= n )
        aib[ p + ZERO(p) ] = max( aib[p + ZERO(p) ] , vec[p] );

}

int main(int argc, char** argv) {

    freopen("arbint.in","r",stdin);
    freopen("arbint.out","w",stdout);

    scanf("%d %d",&n,&m);

    for(int i = 1 ; i <= n ; i++) {
        scanf("%d",&nr);
        //update(i,nr);
        construct(i,nr);
    }

    for(int i = 1 ; i <= m ; i++) {
        scanf("%d %d %d",&o,&a,&b);
        if(o == 0)
            printf("%d\n",query(a,b));
        else
            update(a,b);
    }

    fclose(stdin);
    fclose(stdout);
    return 0;
}
/*
/// time = 0.192
#include <iostream>
#include <cstdio>

using namespace std;

#define in "arbint.in"
#define out "arbint.out"
#define dim 100001

int N, M;
int MaxArb[dim<<2];
int start, finish, Val, Pos, maxim;

inline int Maxim(int a, int b) {
       if ( a > b ) return a;
       return b;
}

void Update(int,int,int);
void Query(int,int,int);

int main()
{
    int X, A, B;
    freopen(in,"rt",stdin);
    freopen(out,"wt",stdout);

    scanf("%d%d", &N, &M);
    for ( int i = 1; i <= N; i++ )
    {
        scanf("%d", &X);
        Pos = i, Val = X;
        Update(1,1,N);
    }

    for ( int i = 1; i <= M; i++ )
    {
        scanf("%d%d%d", &X, &A, &B);
        if ( X == 0 )
        {
             maxim = -1;
             start = A, finish = B;
             Query(1,1,N);

             printf("%d\n", maxim);
        }
        else
        {
            Pos = A, Val = B;
            Update(1,1,N);
        }
    }

    fclose(stdin);
    fclose(stdout);
    return 0;
}

void Update(int nod, int left, int right)
{
     if ( left == right )
     {
          MaxArb[nod] = Val;
          return;
     }

     int div = (left+right)>>1;
     if ( Pos <= div ) Update(nod<<1,left,div);
     else              Update((nod<<1)+1,div+1,right);

     MaxArb[nod] = Maxim( MaxArb[2*nod], MaxArb[2*nod+1] );
}

void Query(int nod, int left, int right)
{
     if ( start <= left && right <= finish )
     {
          if ( maxim < MaxArb[nod] ) maxim = MaxArb[nod];
          return;
     }

     int div = (left+right)>>1;
     if ( start <= div ) Query(nod<<1,left,div);
     if ( div < finish ) Query((nod<<1)+1,div+1,right);
}
*/
/*
#include <stdio.h>

#define NX (1<<17)
#define INF (0x3f3f3f3f)

int T[ NX ], a[ NX ];
int N, M;

int que( int l, int r ) {
    int p, q, m = 0;

    for( p=r-(r&-r); l<=r; r=p, p-=p&-p ) {
        q = ( p+1 >= l ) ? T[r] : (p=r-1) + 1;
        if( a[m] < a[q] )
            m = q;
    }

    return m;
}

void upd( int x ) {
    int y, z;
    for( y = x; x <= N; x += x & -x )
        if( T[x] == y ) {
            z = que( x-(x&-x) + 1, x-1 );
            T[x] = (a[z] > a[x]) ? z : x;
        }
        else
            if( a[ T[x] ] < a[ y ] )
                T[x] = y;
}

int main() {
    int i, x, y, op;

    freopen( "arbint.in", "r", stdin );
    freopen( "arbint.out", "w", stdout );

    a[0] = -INF;
    scanf( "%d%d", &N, &M );

    for( i = 1; i <= N; i++ ) {
        scanf( "%d", a+i );
        upd( i );
    }

    while( M-- ) {
        scanf( "%d%d%d", &op, &x, &y );
        if( op == 0 )
            printf( "%d\n", a[ que( x, y ) ] );
        else
            a[x] = y, upd( x );
    }

    fclose(stdin);
    fclose(stdout);
    return 0;
}
*/