#include <bits/stdc++.h>
using namespace std;
#pragma GCC optimize("Ofast")
long long gcd(long long a, long long b) { return b ? gcd(b, a % b) : a; };
long long lcm(long long a, long long b) { return a / gcd(a, b) * b; };
long long mod(long long a, long long b) { return (a + b - 1) / b; };
long long month[12] = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
template <typename A, size_t N, typename T>
void Fill(A (&array)[N], const T& val) {
  std::fill((T*)array, (T*)(array + N), val);
}
template <class T>
inline bool chmax(T& a, T b) {
  if (a < b) {
    a = b;
    return true;
  }
  return false;
};
template <class T>
inline bool chmin(T& a, T b) {
  if (a > b) {
    a = b;
    return true;
  }
  return false;
};
signed main() {
  cin.tie(0);
  cout.tie(0);
  ios::sync_with_stdio(false);
  long long n, h;
  cin >> n >> h;
  long long a[n + 10], b[n + 10];
  long long lim = 0;
  for (long long(i) = 0; i < (n); i++) {
    cin >> a[i] >> b[i];
    chmax(lim, a[i]);
  }
  sort(b, b + n, greater<long long>());
  long long i;
  for (i = 0; b[i] >= lim; i++) {
    h -= b[i];
    if (h <= 0) {
      cout << i + 1 << endl;
      return 0;
    }
  }
  while (1) {
    h -= lim;
    i++;
    if (h <= 0) {
      cout << i << endl;
      return 0;
    }
  }
  return 0;
}
