#include <bits/stdc++.h>
using namespace std;
int main() {
  long long n, h;
  cin >> n >> h;
  vector<long long> a(n);
  vector<long long> b(n);
  long long amax = 0, abmax = 0;
  long long sum = 0;
  int num = 0;
  long long count = 0;
  for (int i = 0; i < n; i++) {
    cin >> a[i] >> b[i];
    if (a[i] > amax) {
      amax = a[i];
      num = i;
      abmax = b[i];
    } else if (a[i] == amax) {
      if (b[i] > abmax) {
        num = i;
        abmax = b[i];
      }
    }
  }
  for (int i = 0; i < n; i++) {
    if (b[i] >= amax && i != num) {
      count++;
      sum += b[i];
    }
    if (sum >= h) {
      cout << count << endl;
      return 0;
    }
  }
  if (sum >= h) {
  } else if (sum + abmax < h) {
    sum += abmax;
    count++;
    long long tmp = (h - sum) % amax;
    if (tmp == 0) {
      count += (h - sum) / amax;
    } else {
      count += 1 + (h - sum) / amax;
    }
  } else {
    count++;
  }
  cout << count << endl;
  return 0;
}
