Library Session Checkout Gaps

A community library logs two independent streams of activity: every time a patron badges into the reading room (a sign-in session), and every time a book is checked out, with each checkout tagged with the sign-in session during which it happened. A single session can have any number of checkouts, including none at all. The head librarian wants to identify, for each patron, how many of that patron's sessions were completely checkout-free.

Input format

Line 1: two integers S and C — the number of sign-in sessions and the number of checkout records. Next S lines: two integers sessionId patronId — sessionId is unique across the S lines, and patronId identifies which patron owns that session (a patron may own many sessions). Next C lines: two integers checkoutId sessionId — checkoutId is unique across the C lines, and sessionId refers to one of the sessions listed above.

Output format

For every patron who has at least one checkout-free session, print a line patronId count, where count is the number of that patron's sessions that had zero checkouts. Print one line per qualifying patron, sorted by patronId ascending. If no patron qualifies, print nothing.

Constraints

• 1 <= S <= 2000
• 0 <= C <= 5000
• 1 <= sessionId, checkoutId, patronId <= 10^6
• Every sessionId that appears among the checkout records also appears among the sign-in sessions

3 1
1 100
2 100
3 200
10 1

100 1
200 1

4 2
1 5
2 5
3 5
4 9
100 2
101 4

5 2