#include <bits/stdc++.h>
using namespace std;
using ll = long long;
int main() {
  int N, H;
  cin >> N >> H;
  vector<int> a(N), b(N);
  for (int i = 0; i < (N); ++i) cin >> a[i] >> b[i];
  int mx = 0;
  for (int i = 0; i < (N); ++i) mx = max(mx, a[i]);
  sort(b.rbegin(), b.rend());
  int cnt = (H + mx - 1) / mx;
  int sum = 0;
  for (int i = 0; i < (N); ++i) {
    sum += b[i];
    cnt = min(cnt, (H - sum + mx - 1) / mx + i + 1);
  }
  cout << cnt << endl;
}
