#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  long long h;
  cin >> n >> h;
  vector<long long> a(n), b(n);
  for (int(i) = 0; (i) < (n); i++) {
    cin >> a[i] >> b[i];
  }
  sort(a.begin(), a.end(), greater<long long>());
  sort(b.begin(), b.end(), greater<long long>());
  long long bmax = 1e9;
  long long count = 0;
  int j = 0;
  while (a[0] <= bmax || h <= 0) {
    bmax = b[j];
    if (a[0] <= bmax) {
      h -= bmax;
      ++count;
    }
    ++j;
  }
  if (h <= 0)
    ;
  else if (h % a[0] == 0) {
    count += h / a[0];
  } else {
    count += h / a[0] + 1;
  }
  cout << count << endl;
  return 0;
}
