#include <bits/stdc++.h>
using namespace std;
const long long MOD = 1e9 + 7;
const long long inf = 1LL << 60;
const int int_inf = 100000000;
const double eps = 1e-9;
const int dx[4] = {1, 0, -1, 0};
const int dy[4] = {0, 1, 0, -1};
template <class T>
inline bool chmax(T& a, T b) {
  if (a < b) {
    a = b;
    return 1;
  }
  return 0;
}
template <class T>
inline bool chmin(T& a, T b) {
  if (a > b) {
    a = b;
    return 1;
  }
  return 0;
}
int main() {
  long long n, h, cnt = 0;
  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());
  sort(b.begin(), b.end());
  int tmp = a[n - 1], idx;
  for (int i = n - 1; i >= 0; i--) {
    if (tmp <= b[i])
      idx = i;
    else
      break;
  }
  for (int i = n - 1; i >= idx; i--) {
    if (h <= 0) {
      cout << cnt << endl;
      return 0;
    }
    h -= b[i];
    cnt++;
  }
  cnt += (h + 1) / a[n - 1];
  cout << cnt << endl;
  return 0;
}
