#include <bits/stdc++.h>
using namespace std;
long long gcd(long long a, long long b) {
  if (a < b) swap(a, b);
  if (a % b == 0)
    return b;
  else
    return gcd(b, a % b);
}
long long lcm(long long a, long long b) {
  long long c = gcd(a, b);
  return ((a / c) * (b / c) * c);
}
const long long INF = 1e18 + 7;
const long long MOD = 1e9 + 7;
int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  long long N, H;
  cin >> N >> H;
  vector<long long> A, B;
  for (long long i = (0); i < (N); ++i) {
    long long a, b;
    cin >> a >> b;
    A.push_back(a);
    B.push_back(b);
  }
  long long ans = 0;
  (sort(A.begin(), A.end()));
  (sort(B.begin(), B.end()));
  (reverse(A.begin(), A.end()));
  (reverse(B.begin(), B.end()));
  for (long long i = (0); i < (N); ++i) {
    if (A[0] < B[i]) {
      H -= B[i];
      ans++;
    } else {
      break;
    }
    if (H < 0) break;
  }
  if (H < 0) {
    cout << ans << endl;
  } else {
    ans += (H + A[0] - 1) / A[0];
    cout << ans << endl;
  }
}
