#include <bits/stdc++.h>
using namespace std;
const int inf = 1001001001;
const int mod = 1000000007;
int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  long long n, h;
  cin >> n >> h;
  vector<long long> a(n), b(n);
  for (int i = 0; i < (n); ++i) cin >> a[i] >> b[i];
  long long res = 0;
  long long t = 0;
  sort((a).rbegin(), (a).rend());
  for (int i = 0; i < (n); ++i) {
    if (b[i] >= a[0]) {
      res++;
      t += b[i];
    }
  }
  if (t >= h) {
    sort((b).begin(), (b).end());
    long long p = 0;
    long long ans = 0;
    for (int i = 0; i < (n); ++i) {
      if (b[i] >= a[0]) {
        p += b[i];
        ans++;
      }
      if (p >= h) {
        cout << (ans) << endl;
        break;
      }
    }
  } else {
    long long ans = res;
    h -= t;
    ans += h % a[0] == 0 ? h / a[0] : floor(h / a[0]) + 1;
    cout << (ans) << endl;
  }
  return 0;
}
