#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;
  vector<int> v;
  vector<int> v2;
  int table[10001][3] = {0};
  int wa = 0;
  int max_r = -1;
  for (int i = 0; i < n; i++) {
    int a, b;
    cin >> a >> b;
    v.push_back(b);
    max_r = max(a, max_r);
  }
  int count = 0;
  sort(v.begin(), v.end());
  for (int i = 0; i < n; i++) {
    if (v[i] >= max_r) {
      wa += v[i];
      count++;
    }
  }
  if (max_r == 1) {
    cout << count + (h - wa) << endl;
  } else {
    cout << count + ((1 + h - wa) / max_r) << endl;
  }
}
