#include <bits/stdc++.h>
using namespace std;
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  long long n, h;
  cin >> n >> h;
  long long a[n + 5], b[n + 5];
  for (int i = 0; i < n; i++) cin >> a[i] >> b[i];
  sort(a, a + n);
  sort(b, b + n);
  long long cnt = 0;
  int flag = 0;
  long long sum = 0;
  int i = n - 1;
  while (sum <= h) {
    if (b[i] <= a[n - 1] || i < 0) {
      flag = 1;
      break;
    }
    sum += b[i--];
    cnt++;
  }
  i = n - 1;
  if (flag == 1) {
    h -= sum;
    int quotient = h / a[i];
    if (h % a[i] == 0)
      cout << cnt + quotient << endl;
    else {
      cout << cnt + quotient + 1 << endl;
    }
  } else {
    cout << cnt << endl;
  }
  return 0;
}
