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

int main() {
  int n, h;
  cin>>n>>h;
  int a[n], b[n];
  for (int i=0; i<n; i++) cin>>a[i]>>b[i];
  sort(a, a + n);
  reverse(a, a + n);
  sort(b, b + n);
  reverse(b, b + n);
  int i = 0;
  int ans = 0;
  while (i < n && a[0] < b[i] && 0 < h) {
    h -= b[i];
    ++i;
    ++ans;
  }
  if (h > 0) {
    ans += (h - 1) / a[0] + 1;
  }
  cout<<ans<<endl;
}