一日一プロ

using System;

namespace atcoder
{
	class MainClass
	{
		public static void Main (string[] args)
		{
			int s, e,sum;

			sum = 0;
			for (int i = 0; i < 3; i++) {
				string[] str = Console.ReadLine ().Split (' ');
				s = int.Parse (str [0]);
				e = int.Parse (str [1]);

					sum +=  s * e / 10;
			}

			Console.WriteLine ("{0}",sum);
		}
	}
}