#include <bits/stdc++.h>
using namespace std;
string to_string(string s) { return '"' + s + '"'; }
string to_string(const char* s) { return to_string((string)s); }
string to_string(bool b) { return (b ? "true" : "false"); }
template <typename A, typename B>
string to_string(pair<A, B> p) {
  return "(" + to_string(p.first) + ", " + to_string(p.second) + ")";
}
template <typename A>
string to_string(A v) {
  bool first = true;
  string res = "{";
  for (const auto& x : v) {
    if (!first) {
      res += ", ";
    }
    first = false;
    res += to_string(x);
  }
  res += "}";
  return res;
}
void debug_out() { cerr << endl; }
template <typename Head, typename... Tail>
void debug_out(Head H, Tail... T) {
  cerr << " " << to_string(H);
  debug_out(T...);
}
void solve(__attribute__((unused)) int tc = 0) {
  int n;
  long long h, x, y;
  vector<long long> a, b;
  cin >> n >> h;
  for (int _ = (0); _ < int(n); _++) {
    cin >> x >> y;
    a.push_back(x);
    b.push_back(y);
  }
  sort(a.begin(), a.end(), greater<long long>());
  sort(b.begin(), b.end(), greater<long long>());
  long long p = a[0];
  long long k = 0, t = 0;
  for (int i = (0); i < int(b.size()); i++) {
    if (b[i] > p) {
      k++;
      t += b[i];
    }
  }
  long long m = ceil((double)(h - t) / (double)p);
  cout << ((long long)m + (long long)k) << endl;
  return;
}
int main() {
  cin.tie(0);
  ios_base::sync_with_stdio(false);
  solve();
}
