#include <bits/stdc++.h>
using namespace std;
using ll = long long;
int main() {
  ll n, h;
  cin >> n >> h;
  ll a[1 << 20], b[1 << 20];
  ll maxshake = 0, j = 0;
  for (int i = 0; i < n; i++) {
    cin >> a[i] >> b[i];
    if (maxshake < a[i]) {
      j = b[i];
      maxshake = a[i];
    }
    if (b[i] < j && maxshake == a[i]) j = b[i];
  }
  sort(b, b + n);
  ll k = 0;
  for (int i = 0; i < n; i++) {
    if (b[i] == j) {
      k = i;
      break;
    }
  }
  ll ans = 0;
  for (int i = n - 1; i > k && h > 0; i--) {
    h -= b[i];
    ans++;
  }
  if (h < 1)
    cout << ans << endl;
  else {
    while (h > 0) {
      if (h <= j)
        h -= j;
      else
        h -= a[k];
      ans++;
    }
    cout << ans << endl;
  }
}
