Kopatych's Fence#212
To protect his garden beds from uninvited visitors, a farmer decided to build a fence. His friends wanted to give him a birthday gift by helping with this challenging task. To surprise their friend, everyone agreed to participate in building the fence. To keep it a secret, they worked at night, with each one constructing a part of the fence. Unfortunately, in the darkness, the sections of the fence ended up scattered across the garden. When morning came, they saw their handiwork and decided to remove the extra parts, leaving only the longest straight section of the fence.
The first line contains the number (N \leq 100000) — the number of friends who participated in the fence construction. Each of the following lines contains four integers x_1, y_1, x_2, y_2 — the coordinates of the starting and ending points of the fence built by the -th friend.
The coordinates do not exceed in absolute value.
Output one real number with six decimal places — the desired length of the fence.
Example 1