#!/usr/bin/env ruby
require 'csv'

kuni = CSV.read("capital.csv", headers:true)

kuni.each do |row|
  printf("%s の首都は %s です。\n", row["国"], row["首都"])
end

print("足したい国: ")
country = gets.chomp
print("首都: ")
capital = gets.chomp

CSV.open("capital.csv", "a") do |c|
  c << [country, capital]
end