#include <bits/stdc++.h>
using namespace std;
void solve1() {
  long long n, h;
  cin >> n >> h;
  vector<long long> a(n), b(n);
  long long sum = 0;
  for (int i = 0; i < n; i++) {
    cin >> a[i] >> b[i];
  }
  sort(a.begin(), a.end());
  long long maxa = a[n - 1];
  long long thcnt = 0;
  long long ansb = 0;
  for (int i = 0; i < n; i++) {
    if (b[i] > maxa) {
      sum += b[i];
      thcnt++;
      if (sum >= h && ansb == 0) {
        ansb = thcnt;
      }
    }
  }
  if (ansb == 0) {
    ansb = 1000000000000000;
  }
  long long ans = thcnt;
  if (sum < h) {
    h -= sum;
    ans += ceil(1.0 * h / maxa);
  }
  cout << min({ans, ansb}) << endl;
}
int main() { solve1(); }
