#include<bits/stdc++.h>
using namespace std;
int main(){
  long N,H;cin>>N>>H;
  vector<long>A(N),B(N);
  for(long i=0;i<N;i++)cin>>A[i]>>B[i];
  sort(A.begin(),A.end(),greater<int>());
  sort(B.begin(),B.end(),greater<int>());
  long i=0;long ans=0;
  while(B[i]>A[0]&&H>0){
    H-=B[i];i++;ans++;
  }
  if(H<=0)cout<<ans;
  else cout<<ans+H/A[0]+(H%A[0]!=0);
  
}