#include <bits/stdc++.h>
using namespace std;
int dx[] = {0, 0, 1, -1, 1, -1, 1, -1};
int dy[] = {1, -1, 0, 0, -1, 1, 1, -1};
long long gcd(long long a, long long b) { return !b ? a : gcd(b, a % b); }
long long lcm(long long a, long long b) { return (a / gcd(a, b)) * b; }
void PLAY() {
  cout << fixed << setprecision(10);
  ios::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
}
int main() {
  long long n, h;
  cin >> n >> h;
  vector<long long> a(n), b(n);
  long long mx = INT_MIN;
  for (int i = 0; i < n; i++) {
    cin >> a[i] >> b[i];
    mx = max(mx, a[i]);
  }
  sort(b.begin(), b.end());
  long long res = 0;
  for (int i = n - 1; i > 0; i--) {
    h -= b[i], res++;
    if (h <= 0) break;
  }
  if (h > 0) {
    res += h / mx;
    h -= h * (h / mx);
    if (h > 0) res++;
  }
  cout << res << endl;
  return 0;
}
