#include <bits/stdc++.h>
using namespace std;
using ll = long long;
const int INF = (1 << 30);
const ll INFL = (1LL << 62);
const int MOD = 1000000007;
template <class T>
bool chmin(T& a, T b) {
  if (a > b) {
    a = b;
    return true;
  }
  return false;
}
template <class T>
bool chmax(T& a, T b) {
  if (a < b) {
    a = b;
    return true;
  }
  return false;
}
template <class T>
T gcd(T a, T b) {
  return b ? gcd(b, a % b) : a;
}
template <class T>
T lcm(T a, T b) {
  return a / gcd(a, b) * b;
}
template <class T>
ll mod_pow(ll a, ll n, T mod) {
  mod = (ll)mod;
  ll res = 1, p = a % mod;
  while (n) {
    if (n & 1) res = res * p % mod;
    p = p * p % mod;
    n >>= 1;
  }
  return res;
}
int main() {
  int N, H;
  cin >> N >> H;
  vector<int> a(N), b(N);
  for (int i = 0; i < (int)(N); i++) cin >> a[i] >> b[i];
  sort((a).begin(), (a).end(), greater<int>());
  sort((b).begin(), (b).end(), greater<int>());
  int ans = 0;
  int i = 0;
  while (b[i] > a[0] && H >= 0) {
    H -= b[i];
    ans++;
    i++;
  }
  ans += ceil((double)H / a[0]);
  cout << ans << endl;
  return 0;
}
