#include<iostream>
#include<algorithm>
using namespace std;
int main()
{
  int N;
  int H;
  int x;  
  cin>>N>>H;
  int a[100010],b[100010];
  for(int i=0;i<N;i++)
     cin>>a[i]>>b[i];
  sort(a,a+N);
  x=a[N-1]; 
  sort(b,b+N); 
  int ans=0;
  for(int j=N;j>=0;j--)
  {
     if(x<b[j] and H>0)
     { H=H-b[j];
       ans++;}
  }
  if(H>0)
  ans+=(H+x-1)/x;
  //cout<<H<<(H+x-1)/x;
  cout<<ans<<endl;
 return 0;
}