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