#include <bits/stdc++.h>
using namespace std;
int main() {
  long long n, h, m = 0, s = 0, c = 0;
  cin >> n >> h;
  vector<long long> a(n), b(n);
  for (int i = 0; i < n; i++) {
    cin >> a[i] >> b[i];
    s += b[i];
    if (m < a[i]) m = a[i];
  }
  if (s >= h) {
    sort(b.begin(), b.end(), greater<long long>());
    for (int i = 0; i < n; i++) {
      h -= b[i];
      c++;
      if (h <= 0) {
        cout << c;
        return 0;
      }
    }
  } else {
    h -= s;
    c += n;
    if (h % m != 0) c++;
    c += h / m;
    cout << c;
  }
}
