#include <bits/stdc++.h>
using namespace std;
const long long mod = 1000000007;
const int INF = 1001001001;
long long n, h;
vector<long long> a, b;
int main() {
  cin >> n >> h;
  a.resize(n, 0);
  b.resize(n, 0);
  for (int i = 0; i < n; i++) {
    cin >> a.at(i);
    cin >> b.at(i);
  }
  sort(a.rbegin(), a.rend());
  sort(b.rbegin(), b.rend());
  long long i = 0, ans = 0;
  while (true) {
    long long x = b.at(i);
    if (x <= a.at(0)) break;
    h -= x;
    ans++;
    if (h <= 0) break;
    if (i == n - 1) break;
    i++;
  }
  while (true) {
    long long x = a.at(0);
    h -= x;
    ans++;
    if (h <= 0) break;
  }
  cout << ans << endl;
}
