#include <bits/stdc++.h>
template <class T>
bool chmin(T &a, T b) {
  if (a > b) {
    a = b;
    return 1;
  }
  return 0;
}
template <class T>
bool chmax(T &a, T b) {
  if (a < b) {
    a = b;
    return 1;
  }
  return 0;
}
using namespace std;
using vint = vector<int>;
using vvint = vector<vector<int>>;
using ll = long long;
using vll = vector<ll>;
using vvll = vector<vector<ll>>;
using P = pair<int, int>;
const int inf = 1e9;
const ll inf_l = 1e18;
const int MAX = 1e5;
int main() {
  int n, h;
  cin >> n >> h;
  vint a(n), b(n);
  for (int i = 0; i < (int)(n); i++) cin >> a[i] >> b[i];
  sort(b.rbegin(), b.rend());
  sort(a.rbegin(), a.rend());
  int ct = 0;
  for (int i = 0; i < (int)(n); i++) {
    if (a[0] <= b[i]) {
      h -= b[i];
      ct++;
      if (h < 0) {
        cout << ct << endl;
        return 0;
      }
    } else
      break;
  }
  if (h > 0) ct += (h + a[0] - 1) / a[0];
  cout << ct << endl;
}
