#!/usr/bin/env ruby

input = $stdin.readlines.map(&:chomp).sort

currentguard = nil
guards = Hash.new { |h,k| h[k] = Hash.new { |h,k| h[k] = Array.new(60, false) } }

(0...input.length).each do |i|
  if input[i] =~ /\[1518-\d\d-\d\d \d\d:\d\d\] Guard #(\d+) begins shift/
    currentguard = $1.to_i
  elsif input[i] =~ /\[1518-(\d\d-\d\d) \d\d:(\d\d)\] falls asleep/
    date = $1
    smin = $2.to_i
    input[i+1] =~ /\[1518-\d\d-\d\d \d\d:(\d\d)\] wakes up/
    emin = $1.to_i
    (smin...emin).each do |m|
      guards[currentguard][date][m] = true
    end
  else
    next
  end
end

times = []
guards.each do |id, days|
  sum = 0
  days.each_value do |day|
    sum += day.count(true)
  end
  times[id] = sum
end

sleepiestguard = times.index(times.compact.max)

minutes = Array.new(60, 0)

(0...60).each do |m|
  guards[sleepiestguard].each_value do |mins|
    minutes[m] += 1 if mins[m]
  end
end

sleepiestminute = minutes.index(minutes.max)

puts sleepiestguard * sleepiestminute