# frozen_string_literal: true
in_n = gets.chomp.to_i
in_ab = in_n.times.map { gets.chomp.split.map(&:to_i) }

max = 1
in_ab.sort!
while !in_ab.empty? && in_ab[0][0] <= max
  max = [max, in_ab.shift[1]].max
end

puts max