#include <bits/stdc++.h>
#pragma GCC optimize("O3")
using namespace std;
long long GCD(long long a, long long b) { return b ? GCD(b, a % b) : a; }
long long LCM(long long a, long long b) { return a / GCD(a, b) * b; }
int dx[8] = {-1, 0, 1, 0, 1, 1, -1, -1};
int dy[8] = {0, -1, 0, 1, 1, -1, 1, -1};
char dir[4] = {'u', 'l', 'd', 'r'};
long long int cmp1(pair<long long int, string> a,
                   pair<long long int, string> b) {
  if (a.first != b.first)
    return a.first < b.first;
  else
    return a.second < b.second;
}
long long int permutation(long long int n, long long int r) {
  long long int a = 1;
  for (long long int i = n - r + 1; i <= n; i++) {
    a *= i;
    a %= 1000000007;
  }
  return a;
}
int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  long long int n, h;
  cin >> n >> h;
  vector<long long int> a(n), b(n);
  for (long long int i = 0; i < n; i++) cin >> a[i] >> b[i];
  sort((a).begin(), (a).end());
  sort((b).begin(), (b).end());
  reverse((a).begin(), (a).end());
  reverse((b).begin(), (b).end());
  long long int ans = 0;
  if (h % a[0] == 0)
    ans = h / a[0];
  else
    ans = h / a[0] + 1;
  long long int useda = ans;
  long long int damage = ans * a[0];
  vector<long long int> usedb;
  for (long long int i = 0; i < ans; i++) {
    if (b[i] > a[0]) {
      damage = damage - a[0] + b[i];
      usedb.push_back(b[i]);
      useda--;
    } else
      break;
  }
  while (damage - a[0] >= h && useda--) {
    damage -= a[0];
    ans--;
  }
  long long int i = 0;
  while (damage - usedb[i] >= h) {
    damage -= usedb[i];
    i++;
    ans--;
    if (i >= (long long int)(usedb).size()) break;
  }
  cout << ans << endl;
  return 0;
}
