using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApp4
{
    class Program
    {
        static void Main(string[] args)
        {
            var t = Console.ReadLine().Split(' ').Select(x => long.Parse(x)).ToArray();
            var N = t[0];
            var H = t[1];

            long maxA = -1;
            List<long> bList = new List<long>();
            for (int i = 0; i < N; i++)
            {
                t = Console.ReadLine().Split(' ').Select(x => long.Parse(x)).ToArray();
                var a = t[0];
                var b = t[1];

                if (maxA < a)
                    maxA = a;

                bList.Add(b);
            }

            bList.Sort();

            var bStrong = bList.Where(x => x > maxA).ToList();
            var bStrongNum = bStrong.Count();
            var bStrongH = bStrong.Sum();

            long ans;
            if (H - bStrongH > 0)
            {
                ans = bStrongNum + ((H - bStrongH) / maxA);
                if ((H - bStrongH) % maxA >0)
                    ans++;
            }
            else
            {
                ans = bStrongNum;
            }

            Console.WriteLine(ans);

        }
    }
}
