#include<iostream>
#include <vector>
#include <algorithm>
using namespace std;
int main(){
int n,h;
int ct=0,c,e;
cin>>n>>h;
vector <int> b;
int max=0;
for(int i=0;i<n;i++){
  cin>>c>>e;
  b.push_back(e);
  if(c>max)max=c;
}
sort(b.begin(),b.end(),greater<int>());
int i=0;
while(b[i]>max){
  h-=b[i];
  ct++;
  if(h<=0)break;
  i++;
}
if(h>0){
  ct+=h/max;
  if(h%max!=0)ct++;
}
cout<<ct<<endl;
  return 0;
}
