#include <bits/stdc++.h>
using namespace std;
class UnionFind {
 public:
  vector<int> Parent;
  UnionFind(int N) { Parent = vector<int>(N, -1); }
  int root(int A) {
    if (Parent[A] < 0) return A;
    return Parent[A] = root(Parent[A]);
  }
  int size(int A) { return -Parent[root(A)]; }
  bool connect(int A, int B) {
    A = root(A);
    B = root(B);
    if (A == B) {
      return false;
    }
    if (size(A) < size(B)) swap(A, B);
    Parent[A] += Parent[B];
    Parent[B] = A;
    return true;
  }
};
long long GCD(long long a, long long b) {
  if (b == 0)
    return a;
  else
    return GCD(b, a % b);
}
long long extGCD(long long a, long long b, long long &x, long long &y) {
  if (b == 0) {
    x = 1;
    y = 0;
    return a;
  }
  long long d = extGCD(b, a % b, y, x);
  y -= a / b * x;
  return d;
}
bool check(pair<long long int, long long int> a,
           pair<long long int, long long int> b) {
  if (a.first == b.first) {
    return b.second < a.second;
  }
  return a.first < b.first;
}
int main() {
  long long int n, h;
  cin >> n >> h;
  vector<pair<long long int, long long int>> a(n);
  vector<pair<long long int, long long int>> b(n);
  for (int i = 0; i < n; i++) {
    cin >> a[i].first >> a[i].second;
    b[i].first = a[i].second;
    b[i].second = a[i].first;
  }
  sort(a.begin(), a.end(), check);
  sort(b.begin(), b.end());
  long long int cnt = 0;
  long long int ans = 0;
  for (int i = n - 1; cnt < h && 0 <= i && a[n - 1].first < b[i].first; i--) {
    if (b[i].second != a[n - 1].first || b[i].first != a[i].second) {
      cnt += b[i].first;
      ans++;
    }
  }
  if (cnt >= h)
    cout << ans << endl;
  else {
    ans +=
        (h - cnt - a[n - 1].second + a[n - 1].first - 1) / a[n - 1].first + 1;
    cout << ans << endl;
  }
  return 0;
}
