def matrix_chain_order(input_array)
  n = input_array.length-1
  array = Array.new(n+1).map{Array.new(n+1,0)}
  2.upto n do |l|
    1.upto n-l+1 do |i|
      j = i+l-1
      array[i][j] = Float::INFINITY
      i.upto j-1 do |k|
        q = array[i][k] + array[k+1][j] + input_array[i-1]*input_array[k]*input_array[j]
        array[i][j] = (array[i][j] > q) ? q : array[i][j]
      end
    end
  end
  puts array[1].last
end

array = []

n = gets.to_i
n.times do |i|
  input = gets.split(" ")
  array << input[0].to_i if i == 0
  array << input[1].to_i
end

matrix_chain_order(array)

