#include <iostream>
#include <algorithm>
using namespace std;
int main(void){
  int n,h,i,a[100010],b[100010],ans=0;
  cin >> n >> h;
  for (i=0;i<n;i++) cin >> a[i] >> b[i];
  sort(a,a+n,greater<int>());
  sort(b,b+n,greater<int>());
  i=0;
  while (h>0 && b[i]>a[0]){
    h-=b[i];
    i++;
    ans++;
  }
  if (h>0) ans+=(h+a[0]-1)/a[0];
  cout << ans << endl;
  return 0;
}