#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, h;
  int a[100001] = {};
  int b[100001] = {};
  cin >> n >> h;
  for (int i = 0; i < n; i++) cin >> a[i] >> b[i];
  sort(b, b + n);
  sort(a, a + n);
  int sum = 0;
  for (int i = n - 1; i >= 0; i--) {
    if (h <= 0) break;
    h -= b[i];
    sum++;
  }
  while (h > 0) {
    h -= a[n - 1];
    sum++;
  }
  cout << sum << endl;
  return 0;
}
