using System;

class MainClass
{
    public static void Main(string[] args)
    {
        string[] s = Console.ReadLine().Split(' ');
        int N = int.Parse(s[0]);
        long H = long.Parse(s[1]);
        long[] a = new long[N];
        long[] b = new long[N];
        long sum =0;

        for (int j = 0; j < N;j++)
        {
            string[] s1 = Console.ReadLine().Split(' ');
            a[j] = long.Parse(s1[0]);
            b[j] = long.Parse(s1[1]);

        }

        Array.Sort(a);
        Array.Reverse(a);
        Array.Sort(b);
        Array.Reverse(b);
        int i = 0;

        while(H>0)
        {
            //Console.WriteLine(H);


            if(a[0] >= b[i])
            {
                sum += H / a[0];
                if (H % a[0] > 0) sum++;

                break;

            }
            else
            {
                H -= b[i];
                i++;
            }
            sum++;
        }

        Console.WriteLine(sum);
    }
}