#include <bits/stdc++.h>
using namespace std;
template <typename H>
bool chmin(H& v1, const H v2) {
  if (v1 > v2) {
    v1 = v2;
    return true;
  }
  return false;
}
template <typename H>
bool chmax(H& v1, const H v2) {
  if (v1 < v2) {
    v1 = v2;
    return true;
  }
  return false;
}
template <typename H>
void read(H& head) {
  cin >> head;
}
template <typename H, typename... T>
void read(H& head, T&... tail) {
  cin >> head;
  read(tail...);
}
template <typename H>
void write(H head) {
  cout << head << '\n';
}
template <typename H, typename... T>
void write(H head, T... tail) {
  cout << head << " ";
  write(tail...);
}
template <typename... T>
void die(T... tok) {
  write(tok...);
  exit(0);
}
int main() {
  cin.tie(0)->sync_with_stdio(0);
  cin.exceptions(cin.failbit);
  int n, h;
  read(n, h);
  multiset<int> m;
  int ma = 0;
  for (int i = 0; i < (n); ++i) {
    int a, b;
    read(a, b);
    chmax(ma, a);
    m.insert(b);
  }
  int ans = 0;
  while (h > 0 && m.size() && *m.rbegin() > ma)
    h -= *m.rbegin(), ans++, m.erase(prev(m.end()));
  ans += (h - ma + 1) / ma;
  die(ans);
}
