On a plane
Description
The first line contains a single integer n (1 ≤ n ≤ 1000) — the number of points on a plane.
Each of the next n lines contains two real coordinates xi and yi of the 
point, specified with exactly 2 fractional digits. All coordinates are between - 1000 and 1000, inclusive.
Output a single real number θ — the answer to the problem statement. The absolute or relative error of your answer should be at most 10 - 2.
Input
The first line contains a single integer n (1 ≤ n ≤ 1000) — the number of points on a plane.
Each of the next n lines contains two real coordinates xi and yi of the point, specified with exactly 2 fractional digits. All coordinates are between - 1000 and 1000, inclusive.
Output
Output a single real number θ — the answer to the problem statement. The absolute or relative error of your answer should be at most 10 - 2.
8<br>-2.14 2.06<br>-1.14 2.04<br>-2.16 1.46<br>-2.14 0.70<br>-1.42 0.40<br>-0.94 -0.48<br>-1.42 -1.28<br>-2.16 -1.62<br>
5<br>2.26 1.44<br>2.28 0.64<br>2.30 -0.30<br>1.58 0.66<br>3.24 0.66<br>
8<br>6.98 2.06<br>6.40 1.12<br>5.98 0.24<br>5.54 -0.60<br>7.16 0.30<br>7.82 1.24<br>8.34 0.24<br>8.74 -0.76<br>
5<br>10.44 2.06<br>10.90 0.80<br>11.48 -0.48<br>12.06 0.76<br>12.54 2.06<br>
8<br>16.94 2.42<br>15.72 2.38<br>14.82 1.58<br>14.88 0.50<br>15.76 -0.16<br>16.86 -0.20<br>17.00 0.88<br>16.40 0.92<br>
7<br>20.62 3.00<br>21.06 2.28<br>21.56 1.36<br>21.66 0.56<br>21.64 -0.52<br>22.14 2.32<br>22.62 3.04<br>
5.410<br>
5.620<br>
5.480<br>
6.040<br>
6.040<br>
6.720<br>