customers has columns customer_id and name. orders has columns order_id and customer_id.

Return the customers with no order at all, keeping both columns, sorted by customer_id with the index renumbered from 0.

This is an anti-join: a left merge keeps the unmatched rows, and the rows whose right-hand side came back missing are the answer.

Input

customers =
   customer_id name
0            1  Ann
1            2   Bo
2            3   Cy
3            4   Di
orders =
   order_id  customer_id
0        10            1
1        11            1
2        12            3

Output

   customer_id name
0            2   Bo
1            4   Di