int pot( int a , int n ){
	int ans = 1 , i;
	for ( i = 0 ; i < n ; i++ )
		ans *= a;
	return ans;
}

char *to_des( int n , int h ){
	int k = 0 , r , i;
	while ( pot( h , k + 1 ) <= n ){
		k++;
	}
	char *s = malloc( ( k + 1 ) * sizeof *s );
	for ( i = k ; i >= 0 ; i-- ){
		r = 0;
		while ( ( r + 1 ) * pot( h , i ) <= n && ( r + 1 ) < h )
			r++;
		n -= r * pot( h , i );
		s[k - i] = 48 + r;
	}
	return s;
}