#include <bits/stdc++.h>
using namespace std;
 
int main() {
  int N,H;
  cin >> N >> H;
  vector<int> a(N),b(N);
  int Ma=0;
  for(int i=0;i<N;i++){cin >> a[i] >> b[i]; Ma=max(Ma,a[i]);}
  sort(b.begin(),b.end());
  reverse(b.begin(),b.end());
  int count=0;
  for(int i=0;i<N;i++){
    if(b[i]<Ma){break;}
    count++;
    H-=b[i];
    if(H<=0){cout << i+1 << endl; return 0;}
  }
  cout << count+(Ma+H-1)/Ma << endl;
}