#include <bits/stdc++.h>
using namespace std;
using P = pair<long, long>;
const int mod = 1000000007;
int xCnt[100005];
char xChar[100005];
int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  long n, h;
  cin >> n >> h;
  vector<long> a(n);
  vector<long> b(n);
  for (auto i = 0; i < (n); i++) {
    cin >> a[i] >> b[i];
  }
  sort(a.begin(), a.end(), std::greater<long>());
  sort(b.begin(), b.end(), std::greater<long>());
  long mxa = a[0];
  long idx = 0;
  long res = 0;
  while (idx < n && b[idx] > mxa && h > 0) {
    h -= b[idx];
    idx++;
    res++;
  }
  res += (h + mxa - 1) / mxa;
  cout << res << endl;
}
