#include <bits/stdc++.h>
using namespace std;
int gcd(int a, int b) {
  if (a % b == 0)
    return (b);
  else
    return (gcd(b, a % b));
}
int lcm(int a, int b) { return a * b / gcd(a, b); }
long long pow(long long a, long long b) {
  long long k = b % 30000, h = b / 30000, s = 1;
  for (int i = 0; i < 30000; i++) s = (s * a) % 1000000007;
  long long j = 1;
  if (h != 0)
    for (int i = 0; i < h; i++) j = j * s % 1000000007;
  if (k != 0)
    for (int i = 0; i < k; i++) j = j * a % 1000000007;
  return (j);
}
int main() {
  int n, h;
  cin >> n >> h;
  vector<int> a(n);
  vector<int> b(n);
  for (int i = 0; i < n; i++) cin >> a[i] >> b[i];
  int maxx = 0;
  for (int i = 0; i < n; i++) maxx = max(maxx, a[i]);
  sort(b.begin(), b.end());
  int sum = 0;
  int kaisuu = 0;
  for (int i = n - 1; i >= 0; i--) {
    if (a[i] < maxx) break;
    sum += a[i];
    kaisuu++;
    if (sum >= h) break;
  }
  if (sum < h) {
    kaisuu += (h - sum + 1) / maxx;
  }
  cout << kaisuu << endl;
}
