#include <bits/stdc++.h>
using namespace std;
const int MOD = 1000000007;
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];
  }
  sort(a.begin(), a.end(), greater<int>());
  sort(b.begin(), b.end(), greater<int>());
  vector<long long> sum(n + 1);
  for (int i = 1; i <= n; i++) {
    sum[i] = sum[i - 1] + b[i - 1];
  }
  int ans = h;
  for (int i = 0; i <= n; i++) {
    int hp = h - sum[i];
    int cnt = (hp + a[0] - 1) / a[0];
    ans = min(ans, i + cnt);
  }
  cout << ans << endl;
  return 0;
}
