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

int main(){
  int n,h;cin>>n>>h;
  vector<int>a(n);
  vector<int>b(n);
  int max_a=0;
  for(int i=0;i<n;++i){
    cin>>a[i]>>b[i];
    max_a=max(max_a,a[i]);
  }
  sort(b.begin(),b.end(),greater<int>());
  int ans=0;
  for(int i=0;;++i){
    if(b[i]<=max_a||i==n){
      ans+=h/max_a+bool(h%max_a);
      break;
    }else{
      h-=b[i];
      ++ans;
      if(h<=0)break;
    }
  }
  cout<<ans<<endl;
}
