#include <bits/stdc++.h>
using namespace std;
int main() {
  int N, H;
  cin >> N >> H;
  vector<int> a(N), b(N);
  int A = 0;
  int n = 0;
  for (; n < N; n++) {
    cin >> a[n] >> b[n];
    A = max(A, a[n]);
  }
  sort(b.begin(), b.end(), greater<int>());
  n = 0;
  for (; n < N && A < b[n] && 0 < H; n++) H -= b[n];
  cout << n + (A + H - 1) / A << endl;
  return 0;
}
