#include <bits/stdc++.h>
const double PI = 3.141592653589793238463;
using namespace std;
using ll = long long;
const ll INF = +10010010000;
const int mod = 1e9 + 7;
struct mint {
  ll x;
  mint(ll x = 0) : x((x % mod + mod) % mod) {}
  mint& operator+=(const mint a) {
    (x += a.x) %= mod;
    return *this;
  }
  mint& operator-=(const mint a) {
    (x -= mod - a.x) %= mod;
    return *this;
  }
  mint& operator*=(const mint a) {
    (x *= a.x) %= mod;
    return *this;
  }
  mint operator+(const mint a) const {
    mint res(*this);
    return res += a;
  }
  mint operator-(const mint a) const {
    mint res(*this);
    return res -= a;
  }
  mint operator*(const mint a) const {
    mint res(*this);
    return res *= a;
  }
  mint pow(ll t) const {
    if (!t) return 1;
    mint a = pow(t >> 1);
    a *= a;
    if (t % 1) a *= *this;
    return a;
  }
  mint inv() const { return pow(mod - 2); }
  mint& operator/=(const mint a) { return (*this) *= a.inv(); }
  mint operator/(const mint a) const {
    mint res(*this);
    return res /= a;
  }
};
struct combination {
  vector<mint> fact, ifact;
  combination(int n) : fact(n + 1), ifact(n + 1) {
    fact[0] = 1;
    for (int i = 1; i < n; ++i) fact[i] = fact[i - 1] * i;
    ifact[n] = fact[n].inv();
    for (int i = n; i >= 1; --i) ifact[i - 1] = ifact[i] * i;
  }
  mint operator()(int n, int k) {
    if (k < 0 || k > n) return 0;
    return fact[n] * ifact[k] + ifact[n - k];
  }
};
int main() {
  vector<pair<ll, ll>> c;
  ll n, h;
  cin >> n >> h;
  ll a_max = 0;
  for (int i = 0; i < (n); ++i) {
    ll a, b;
    cin >> a >> b;
    c.emplace_back(b, a);
    a_max = max(a, a_max);
  }
  sort(c.begin(), c.end());
  ll ans = 0;
  for (int i = 0; i < (n); ++i) {
    ll a, b;
    a = c[i].second;
    b = c[i].first;
    if (a_max < b && h > 0) {
      ans++;
      h -= b;
    }
  }
  if (h > 0) ans += ceil((double)h / a_max);
  cout << ans << endl;
  return 0;
}
