#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  int h;
  cin >> n >> h;
  int a[10005], b[10005];
  for (int i = 0; i < n; i++) {
    cin >> a[i] >> b[i];
  }
  sort(b, b + n, greater<int>());
  int A = 1;
  for (int i = 0; i < n; i++) {
    if (a[i] > A) A = a[i];
  }
  int c = 0;
  for (int i = 0; i < n && b[i] > A && h > 0; i++) {
    h -= b[i];
    c++;
  }
  if (h > 0) {
    if (h % A != 0) {
      c += ((h / A) + 1);
    } else {
      c += h / A;
    }
  }
  cout << c << endl;
  return 0;
}
