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