#include <bits/stdc++.h>
using namespace std;
using ll = long long;
const ll MOD = 1e9 + 7;
template <typename T>
T gcd(T a, T b) {
  if (a > b) return gcd(b, a);
  return a == 0 ? b : gcd(b % a, a);
}
template <typename T, typename U>
T mypow(T b, U n) {
  if (n == 0) return 1;
  if (n == 1) return b;
  if (n % 2 == 0) {
    return mypow(b * b, n / 2);
  } else {
    return mypow(b, n - 1) * b;
  }
}
int main() {
  ll N, H;
  cin >> N >> H;
  ll a[N];
  ll b[N];
  for (int i = 0; i < N; i++) {
    cin >> a[i] >> b[i];
  }
  ll bsum = 0;
  ll bnum = 0;
  ll amax = -1;
  for (ll i = 0; i < N; i++) {
    amax = max(amax, a[i]);
  }
  for (ll i = 0; i < N; i++) {
    if (b[i] > amax) {
      bsum += b[i];
      bnum++;
    }
  }
  ll ret = 0;
  if (H > bsum) {
    ret += ceil(1.0 * (H - bsum) / amax);
    ret += bnum;
  } else {
    sort(b, b + N);
    ll sum = 0;
    ll p = 0;
    while (sum < H) {
      ret++;
      sum += b[p++];
    }
  }
  cout << ret << endl;
  return 0;
}
