When I wrote my first version, I had TLE#13.
I optimize it - Crash#13.
Help me with tests or hints. Please.
Thanks.

Edited by author 10.05.2006 20:37

I guess in this test one needs to add to the largest section (and N*M is not very small) -- I had a problem with 1e8 sentinel.

This test helped me a lot.

2 2 10
1 3
2 4

Output is: 5