#include <bits/stdc++.h>
using namespace std;
constexpr long long INF = 1LL << 60;
inline long long in() {
  long long x;
  cin >> x;
  return x;
}
template <typename T>
inline void out(const T &x) {
  cout << x << endl;
}
template <class T>
inline bool chmin(T &a, T b) {
  if (a > b) {
    a = b;
    return 1;
  }
  return 0;
}
template <class T>
inline bool chmax(T &a, T b) {
  if (a < b) {
    a = b;
    return 1;
  }
  return 0;
}
const long long dx[] = {0, 1, 0, -1, 1, -1, 1, -1},
                dy[] = {1, 0, -1, 0, 1, -1, -1, 1};
long long gcd(long long a, long long b) {
  if (a < b) gcd(b, a);
  long long r;
  while ((r = a % b)) {
    a = b;
    b = r;
  }
  return b;
}
void eratos(bool *isPrime, long long max) {
  fill(isPrime, isPrime + max, true);
  isPrime[0] = false;
  isPrime[1] = false;
  for (long long i = 2; i <= max / i; ++i)
    if (isPrime[i])
      for (long long j = 2; j <= max / i; ++j) isPrime[i * j] = false;
}
long long a[100010];
long long b[100010];
signed main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  long long N, H;
  cin >> N >> H;
  for (long long i = 0; i < (N); ++i) cin >> a[i] >> b[i];
  long long max = 0;
  for (long long i = 0; i < (N); ++i) {
    chmax(max, a[i]);
  }
  sort(b, b + N);
  long long cnt = 0;
  for (auto itr = lower_bound(b, b + N, max); itr != b + N; itr++) {
    H -= *itr;
    cnt++;
    if (H <= 0) {
      cout << cnt << endl;
      return 0;
    }
  }
  cout << (H - 1) / max + 1 + cnt << endl;
}
