#include <bits/stdc++.h>
using namespace std;
long long a[100001], b[100001];
int main() {
  int n, h;
  cin >> n >> h;
  long long sum = 0, num = 0, max1 = 0;
  for (int i = 0; i < n; i++) {
    cin >> a[i] >> b[i];
    max1 = max(max1, a[i]);
  }
  for (int i = 0; i < n; i++) {
    if (b[i] >= max1) {
      sum += b[i];
      num++;
    }
  }
  if (sum >= h) {
    sort(b, b + n);
    num = n;
    int i = 0;
    while (sum - b[i] >= h) {
      num--;
      i++;
      sum -= b[i];
    }
    cout << num << endl;
    return 0;
  } else {
    while (sum < h) {
      if (h - max1 * 100000 > sum) {
        h -= max1 * 100000;
        num += 100000;
      } else {
        h -= max1;
        num++;
      }
    }
    cout << num << endl;
    return 0;
  }
}
