#include<bits/stdc++.h>
using namespace std;
using ll=long long;

int main(){
  int i,j;ll cnt=0;
  ll n,h;
  cin>>n>>h;
  ll a[n],b[n];
  for(i=0;i<n;i++)cin>>a[i]>>b[i];
  ll maxa=0;
  for(i=0;i<n;i++)maxa=max(maxa,a[i]);
  sort(b,b+n,greater<int>());
  for(i=0;i<n;i++){
    if(b[i]>maxa){
      h-=b[i];
      cnt++;
    }else break;
    if(h<=0){
      cout<<cnt<<endl;
      return 0;
    }
  }
  cout<<(h+maxa-1)/maxa+cnt<<endl;
}