#include <bits/stdc++.h>
using namespace std;
int main(void) {
  int n, h;
  cin >> n >> h;
  int a[n], b[n];
  for (int i = 0; i < n; i++) cin >> a[i] >> b[i];
  int s = sizeof(b) / sizeof(b[0]);
  sort(b, b + s);
  int mx_a = -1;
  for (int i = 0; i < n; i++)
    if (mx_a < a[i]) mx_a = a[i];
  int c = 0;
  for (int i = n - 1; i > 0; i--) {
    if (b[i] > mx_a) {
      h -= b[i];
      c++;
    } else {
      break;
    }
  }
  if (h > 0) {
    c += h / mx_a;
    h -= h * (h / mx_a);
    if (h > 0) {
      c++;
    }
  }
  cout << c << endl;
  return 0;
}
