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

signed main(){
  int N,H;
  cin>>N>>H;
  std::vector<int> a(N),b(N);
  for(int i=0;i<N;i++)cin>>a[i]>>b[i];
  sort(a.begin(),a.end());
  sort(b.begin(),b.end());
  int i;
  int out=0;
  for(i=0;i<N&&out==0;i++){
    if(b[N-i-1]<a[N-1])break;
    H-=b[N-i-1];
    if(H<=0)out++;
  }
  if(out)cout<<i<<endl;
  else cout<<i+(H-1)/a[N-1]+1<<endl;
}
