#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using vi = vector<long long>;
using vvi = vector<vi>;
using vl = vector<ll>;
using vs = vector<string>;
using P = pair<long long, long long>;
using T = tuple<long long, long long, long long>;
using vp = vector<P>;
using vt = vector<T>;
const long long mod = 1000000007;
const double EPS = 1e-9;
const ll INF = (1LL << 62) - 1;
inline long long in() {
  long long x;
  scanf("%d", &x);
  return x;
}
template <typename T>
inline ll suma(const vector<T>& a) {
  ll res(0);
  for (auto&& x : a) res += x;
  return res;
}
template <class T>
inline bool chmax(T& a, T b) {
  if (a < b) {
    a = b;
    return true;
  }
  return false;
}
template <class T>
inline bool chmin(T& a, T b) {
  if (a > b) {
    a = b;
    return true;
  }
  return false;
}
signed main() {
  long long n, h;
  cin >> n >> h;
  vi a(n), b(n);
  for (long long i = (0); i < (n); ++i) cin >> a[i] >> b[i];
  sort(b.rbegin(), b.rend());
  long long ans = INF;
  long long bbb = 0;
  long long a_mx = *max_element((a).begin(), (a).end());
  for (long long i = (0); i < (n); ++i) {
    bbb += b[i];
    long long tmp = i + 1 + (((h - bbb) + (a_mx)-1) / (a_mx));
    chmin(ans, tmp);
  }
  cout << ans << endl;
  return 0;
}
