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

signed main(){
  int n, h, amax=0, b[100000], ans=0;

  cin >> n >> h;

  int a;
  for(int i=0; i<n; ++i){
    cin >> a >> b[i];
    amax = max(amax, a);
  }

  sort(b, b+n, greater<int>());

  for(int i=0; i<n && h > 0 && b[i] >= amax; ++i){
    h -= b[i];
    ++ans;
  }

  if(h > 0) ans += (h + (amax - 1)) / amax;

  cout << ans << endl;
}


