#include <bits/stdc++.h>
int gcd(int a, int b) {
  int c;
  while (b != 0) {
    c = a % b;
    a = b;
    b = c;
  }
  return a;
}
int lcm(int a, int b) {
  int c = gcd(a, b);
  a /= c;
  return a * b;
}
const int MOD = 1000000007;
const int INF = 1e9;
const long long LINF = INF * 1ll * INF;
const long double DINF = 1e200;
const double EPS = 1e-10;
const double PI = acos(-1.0);
using namespace std;
int arr[1000000];
int a[1000000];
void eratosthenes() {
  for (int i = 0; i < 1000000; i++) {
    arr[i] = 1;
  }
  for (int i = 2; i < sqrt(1000000); i++) {
    if (arr[i]) {
      for (int j = 0; i * (j + 2) < 1000000; j++) {
        arr[i * (j + 2)] = 0;
      }
    }
  }
  arr[0] = 0;
  arr[1] = 0;
}
signed main() {
  int n, h;
  cin >> n >> h;
  int max_a = -1;
  vector<int> v;
  for (int i = 0; i < n; i++) {
    int a, b;
    cin >> a >> b;
    v.push_back(b);
    max_a = max(a, max_a);
  }
  sort(v.rbegin(), v.rend());
  int count = 0;
  for (int i = 0; i < n; i++) {
    if (h <= 0) {
      cout << count << endl;
      return 0;
    }
    if (max_a < v[i]) {
      h -= v[i];
      count++;
    } else
      break;
  }
  cout << count + (h + max_a - 1 / max_a) << endl;
}
