|시간 제한||메모리 제한||제출||정답||맞은 사람||정답 비율|
|2 초||128 MB||15||6||4||36.364%|
At the latest KBTU ”Commencement” party Bakhytzhan noticed that there were n girls D1,D2,...,Dn and 2n−1 boys B1,B2,...,B2n−1. And every girl Dj knows exactly boys B1,B2,...,B2j−1. Throughout the evening party Bakhytzhan tried to count the number of possible choices of exactly r acquainted boys and girls pairs for dancing. That’s why he missed his chance for dancing. Please, write a program that would help Bakhytzhan don’t miss a chance to dance at the next party.
The input file contains two integer numbers n and r (1 ≤ n,r ≤ 106) separated by a space.
Output file should contain answer to Bakhytzhan’s problem – residue modulo 2946859