#include <bits/stdc++.h>
using namespace std;
const int INF = 1e9;
const long long LLINF = 1e18;
const long long MOD = 1000000007;
const int MSIZE = 100007;
const double Pi = 3.14159265358979323146;
int main() {
  int n;
  long long h;
  cin >> n >> h;
  long long maxThrowDamage = 0;
  vector<long long> slashDamage(n), throwDamage(n);
  long long sumThrowDamage = 0;
  long long addAttackCount = 0;
  for (int i = 0; i < (int)(n); i++) {
    long long a, b;
    cin >> a >> b;
    slashDamage[i] = a;
    throwDamage[i] = b;
  }
  sort((slashDamage).rbegin(), (slashDamage).rend());
  sort((throwDamage).rbegin(), (throwDamage).rend());
  for (int i = 0; i < (int)(n); i++) {
    if (throwDamage[i] >= slashDamage[0]) {
      sumThrowDamage += throwDamage[i];
      addAttackCount++;
      continue;
    }
    break;
  }
  long long ans = (h - sumThrowDamage + slashDamage[0] - 1) / slashDamage[0];
  ans += addAttackCount;
  cout << ans << endl;
}
