#include <stdio.h>
#include <stdlib.h>

#define MOD 100000003
#define MAX_N 1000000

char f[1 + MAX_N];

int main() {
    FILE *fin = fopen( "grigo.in", "r" ), *fout = fopen( "grigo.out", "w" );
    int n, m, i, x;
    fscanf( fin, "%d%d", &n, &m );
    for ( i = 0; i < m; i ++ ) {
        fscanf( fin, "%d", &x );
        f[x] = 1;
    }

    long long s = 1;
    for ( i = 1; i <= n; i ++ )
        if ( !f[i] )
            s = s * ( i - 1 ) % MOD;
    fprintf( fout, "%lld", s );

    fclose( fin );
    fclose( fout );

    return 0;
}