n, v, c = read_line.split.map(&.to_i)
dp = Array.new(v + 1, 0)
n.times do
  a, b = read_line.split.map(&.to_i)
  (v - a).downto(0) do |i|
    dp[i + a] = {dp[i + a], dp[i] + b + c}.max
  end
  a.upto(v) do |i|
    dp[i] = {dp[i], dp[i - a] + b}.max
  end
end
puts dp.max