#include<iostream>
#include<algorithm>
#include<cmath>
using namespace std;
int N_MAX = 100000;
int main()
{
  int n,h,a=0,t,i,res=0;
  int b[N_MAX];
  cin >> n >> h;
  for(i=0;i<n;i++){
    cin >> t >> b[i];
    a=max(a,t);
  }
  sort(b,b+n,greater<int>());
  for(i=0;i<n&&h>0;i++){
    if(b[i]<a)
      break;
    h-=b[i];
    res++;
  }
  if(h>0)
    res+=(int)ceil((double)h/a);
  cout << res << endl;
  return 0;
}