#include <bits/stdc++.h>
using namespace std;
long long MOD = 1000000007;
int main() {
  int N;
  long long H;
  cin >> N >> H;
  vector<long long> A(N), B(N);
  for (int i = 0; i < N; i++) {
    cin >> A[i] >> B[i];
  }
  long long a_m = 0, b_m = LLONG_MAX;
  for (int i = 0; i < N; i++) {
    if (a_m <= A[i]) {
      if (b_m == LLONG_MAX) {
        b_m = B[i];
      } else if (a_m < A[i]) {
        b_m = B[i];
      } else if (a_m == A[i] && b_m >= B[i]) {
        b_m = B[i];
      }
      a_m = A[i];
    }
  }
  sort(B.begin(), B.end(), greater<long long>());
  long long ans = 0;
  for (int i = 0; i < N; i++) {
    if (B[i] < b_m) {
      break;
    }
    ans++;
    H -= B[i];
    if (H <= 0) {
      break;
    }
  }
  if (H > 0) {
    ans += (H / a_m) + ((H % a_m) ? 1 : 0);
  }
  cout << ans << endl;
  return 0;
}
