Problems > Binomial Coefficient

Binomial Coefficient

Difficulty: 1500 2000 ms 128 MB

math combinatorics

Compute C(N, K) — the number of ways to choose K items from N — modulo 109+7.

Input: one line with two integers N and K.

Output: C(N, K) mod 109+7.

Constraints:

  • 0 ≤ K ≤ N ≤ 2×105

Sample Tests

Input 1
5 2
Output 1
10
Input 2
10 0
Output 2
1

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