#include <bits/stdc++.h>
using namespace std;
map<int, int> mp;
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  long long n, y, a[100005], i, j, b[100005], d;
  cin >> n >> y;
  for (i = 0; i < n; i++) {
    cin >> a[i] >> b[i];
  }
  sort(a, a + n);
  sort(b, b + n);
  long long sum = 0, c = 0;
  for (int i = 0; i < n; i++) {
    if (a[n - 1] < b[i]) {
      c++;
      sum += b[i];
      if (sum >= y) break;
    }
  }
  if (sum >= y)
    cout << c << endl;
  else if ((y - sum) % a[n - 1] == 0) {
    cout << c + (y - sum) / a[n - 1] << endl;
  } else
    cout << c + (y - sum) / a[n - 1] + 1 << endl;
  return 0;
}
