CodeForces 129A Cookies

输入描述:

The first line contains the only integer n (1 ≤ n ≤ 100) — the number of cookie bags Anna and Maria have. The second line contains n integers ai (1 ≤ ai ≤ 100) — the number of cookies in the i-th bag.

输出描述:

Print in the only line the only number — the sought number of ways. If there are no such ways print 0.

1<br />1<br />10<br />1 2 2 3 4 4 4 2 2 2<br />11<br />2 2 2 2 2 2 2 2 2 2 99<br />

1<br />8<br />1<br />

备注:

In the first sample Olga should take the only bag so that the twins ended up with the even number of cookies.
In the second sample Olga can take any of five bags with two cookies or any of three bags with four cookies — 5 + 3 = 8 ways in total.
In the third sample, no matter which bag with two cookies Olga chooses, the twins are left with 2 * 9 + 99 = 117 cookies. Thus, Olga has only one option: to take the bag with 99 cookies.