#include <bits/stdc++.h>
using namespace std;
long long i, j, k, l;
int main() {
  long long n, h, sum = 0;
  cin >> n >> h;
  vector<long long> a(n), b(n);
  for (i = 0; i < n; i++) {
    cin >> a[i] >> b[i];
  }
  sort(a.begin(), a.end());
  sort(b.begin(), b.end());
  for (i = 0; i < n; i++) {
    if (b[i] <= a[n - 1]) {
      b[i] = -1;
    } else {
      sum += b[i];
    }
  }
  long long ans = 0, num = n - 1;
  while (h > 0 && num >= 0 && b[num] != -1) {
    h -= b[num];
    ans++;
    num--;
  }
  ans += (h + a[n - 1] - 1) / a[n - 1];
  cout << ans << endl;
  return 0;
}
