#include <stdio.h>
#define N_MAX 100000
typedef char bool;

int M, N;
int tree[ 4 * N_MAX + 1 ];

inline int lson( int x ) {
    return 2 * x;
}
inline int rson( int x ) {
    return 2 * x + 1;
}
inline int max( int a, int b ) {
    return a > b ? a : b;
}

void update( int top, int l, int r, int pos, int val ) {
    if( r != l ) {
        int m = ( l + r ) / 2;
        if( pos > m ) {
            update( rson( top ), m + 1, r, pos, val );
        } else {
            update( lson( top ), l, m, pos, val );
        }
        tree[ top ] = max( tree[ lson( top ) ], tree[ rson( top ) ] );
    } else {
        tree[ top ] = val;
    }
}

int query( int top, int l, int r, int beg, int end ) {
    int currmax = -1;
    if( beg <= l && r <= end ) {
        currmax = max( currmax, tree[ top ] );
    } else {
        int m = ( l + r ) / 2;
        if( beg <= m ) {
            currmax = max( currmax, query( lson( top ), l, m, beg, end ) );
        }
        if( m < end ) {
            currmax = max( currmax, query( rson( top ), m + 1, r, beg, end ) );
        }
    }
    return currmax;
}

int main( ) {
    FILE * fin, * fout;
    fin = fopen( "arbint.in", "r" );
    fout = fopen( "arbint.out", "w" );

    int N, M;
    fscanf( fin, "%d%d", &N, &M );
    
    int i;
    for( i = 1; i <= N; i ++ ) {
        int read;
        fscanf( fin, "%d", &read );
        update( 1, 1, N, i, read );
    }
    for( i = 1; i <= M; i ++ ) {
        int type, a, b;
        fscanf( fin, "%d%d%d", &type, &a, &b );
        if( type ) {
            update( 1, 1, N, a, b );
        } else {
            fprintf( fout, "%d\n", query( 1, 1, N, a, b ) );
        }
    }

    fclose( fin );
    fclose( fout );
}