dummy-1-1
Source: hackerearth
Difficulty: UNKNOWN_DIFFICULTY

You are given a binary string (string made up of only 0s and 1s) each day of a week for a week. The value 1 represents a HIGH and 0 represents a LOW. You task is to find the Standard Deviation of HIGH on each day.

Input:
The input contains 7 lines, representing seven days of a week. Each line contains a string of 1s & 0s.

Output:
Output a single line with the result rounded to 4 decimal places, which is the standard deviation of the 1's count on each day.

Constraints:
|string| < 10^6

SAMPLE INPUT
11011
1010000
0010
1101
010
101111
001110

SAMPLE OUTPUT
1.3851