#include <bits/stdc++.h>
using namespace std;
int main() {
  long long int N, H;
  cin >> N >> H;
  long long int a[N];
  long long int b[N];
  long long int a_max = 1;
  long long int b_max = 1;
  long long int a_max_number, b_max_number;
  for (long long int i = 0; i < N; i++) {
    cin >> a[i] >> b[i];
    if (a_max < a[i]) {
      a_max = a[i];
      a_max_number = i;
    }
    if (b_max < b[i]) {
      b_max = b[i];
      b_max_number = i;
    }
  }
  long long int number = 1;
  for (long long int i = 0; i < N; i++) {
    if (i != b_max_number && b[i] > a[a_max_number]) {
      if (a[i] < b[i]) {
        H -= b[i];
        number++;
      }
    }
  }
  while (H > b[b_max_number]) {
    H -= a[a_max_number];
    number++;
  }
  cout << number << endl;
  return 0;
}
