#include <bits/stdc++.h>
using namespace std;
bool compPair(const pair<int, int>& arg1, const pair<int, int>& arg2) {
  return arg1.first > arg2.first;
}
template <class T>
void chmax(T& a, T b) {
  if (a < b) {
    a = b;
  }
}
template <class T>
void chmin(T& a, T b) {
  if (a > b) {
    a = b;
  }
}
int main(void) {
  int n, h;
  cin >> n >> h;
  vector<int> a(n);
  vector<int> b(n);
  int amax = -1, iamax = -1;
  for (int in = 0; in < n; in++) {
    cin >> a.at(in) >> b.at(in);
    if (amax < a.at(in)) {
      amax = a.at(in);
      iamax = in;
    }
  }
  int ans = 0;
  for (int in = 0; in < n; in++) {
    if (in == iamax) continue;
    if (b.at(in) > amax) {
      h -= b.at(in);
      ans++;
    }
  }
  if (h <= b.at(iamax)) {
    cout << ans + 1 << endl;
  } else {
    int ans1 = ans, ans2 = ans;
    ans1 += h / amax;
    if (h % amax != 0) ans1++;
    ans2 += (h - b.at(iamax)) / amax;
    ans2++;
    if ((h - b.at(iamax)) % amax != 0) ans2++;
    cout << min(ans1, ans2) << endl;
  }
  return 0;
}
