#include <bits/stdc++.h>
using namespace std;
const int INF = 1e9;
const int MOD = 1e9 + 7;
const long long LINF = 1e18;
int main() {
  long long n, h;
  cin >> n >> h;
  vector<long long> a(n);
  vector<long long> b(n);
  for (long long i = 0; i < n; ++i) {
    cin >> a[i] >> b[i];
  }
  sort(a.rbegin(), a.rend());
  sort(b.rbegin(), b.rend());
  long long a_max = a[0];
  long long b_sum = 0;
  long long ans = 0;
  for (long long i = 0; i < n; ++i) {
    if (a_max < b[i]) {
      b_sum += b[i];
      ++ans;
    } else {
      break;
    }
  }
  long long t = h - b_sum;
  if (t > 0) {
    if (t % a_max == 0) {
      ans += t / a_max;
    } else {
      ans += t / a_max + 1;
    }
  }
  cout << ans << endl;
}
