#include <bits/stdc++.h>
const int mod = 1000000007;
const int INF = 1LL << 30;
const long long int LLINF = 1LL << 60;
using namespace std;
int main() {
  long long int n, h, a[100010], b[100010];
  cin >> n >> h;
  for (int i = 0; i < n; ++i) cin >> a[i] >> b[i];
  sort(a, a + n);
  sort(b, b + n);
  int ct = 0;
  for (int i = n - 1; i >= 0; --i) {
    if (h <= 0) {
      h = 0;
      break;
    }
    if (b[i] < a[n - 1]) break;
    h -= b[i];
    ++ct;
  }
  cout << (h / a[n - 1]) + ct + (h % a[n - 1] == 0 ? 0 : 1) << endl;
  return 0;
}
