Given a date-indexed Series s, return the sum of the values that fall on a Wednesday (weekday == 2).

Input

2015-01-01      0
2015-01-02      1
2015-01-05      2
2015-01-06      3
2015-01-07      4
             ... 
2015-12-25    256
2015-12-28    257
2015-12-29    258
2015-12-30    259
2015-12-31    260
Freq: B, Length: 261, dtype: int64

Output

6838