require 'pp'

n = gets.chomp!.to_i
points = []

min_x = 99999
max_x = 0
min_y = 99999
max_y = 0

n.times do |i|
    x, y = gets.chomp!.split.map(&:to_i)
    points << [x, y]

    if x < min_x
        min_x = x
    end

    if x > max_x
        max_x = x
    end

    if y < min_y
        min_y = y
    end

    if y > max_y
        max_y = y
    end
end

mid_x = (min_x + max_x).to_f / 2.0
mid_y = (min_y + max_y).to_f / 2.0
diff_x = max_x - min_y
diff_y = max_y - min_y

#pp mid_x
#pp mid_y

memo_left = Array.new(n, 0.0)
n.times do |i|
    memo_left[i] = Math.sqrt((points[i][0] - mid_x) ** 2 + (points[i][1] - mid_y) ** 2)
end

puts memo_left.sort[-1]
