#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using vpii = vector<pair<int, int>>;
const ll mod = 1e9 + 7;
const ll inf = 1e10;
const double pi = 3.141592;
ll gcd(ll a, ll b) { return (b != 0) ? gcd(b, a % b) : a; }
ll lcm(ll a, ll b) { return (a / gcd(a, b)) * b; }
template <class T>
bool contain(const string& s, const T& v) {
  return s.find(v) != std::string::npos;
}
ll f(int a, int b) {
  if (a == b || a == 0 || b == 0)
    return 1;
  else
    return f(a - 1, b - 1) % mod + f(a - 1, b) % mod;
}
int main() {
  cin.tie(0);
  ios_base::sync_with_stdio(false);
  int n, h;
  cin >> n >> h;
  priority_queue<int> a, b;
  for (int i = 0; i < (int)n; i++) {
    int ta, tb;
    cin >> ta >> tb;
    a.push(ta);
    b.push(tb);
  }
  int ans = 0;
  int amax = a.top();
  while (h > 0 && amax < b.top()) {
    h -= b.top();
    b.pop();
    ++ans;
  }
  while (h > 0) {
    h -= amax;
    ++ans;
  }
  cout << ans << "\n";
  return 0;
}
