#include <bits/stdc++.h>
using namespace std;
int dx[] = {0, 0, 1, -1, -1, -1, 1, 1};
int dy[] = {1, -1, 0, 0, -1, 1, 1, -1};
template <class T>
inline T biton(T n, T pos) {
  return n | ((T)1 << pos);
}
template <class T>
inline T bitoff(T n, T pos) {
  return n & ~((T)1 << pos);
}
template <class T>
inline T ison(T n, T pos) {
  return (bool)(n & ((T)1 << pos));
}
template <class T>
inline T gcd(T a, T b) {
  while (b) {
    a %= b;
    swap(a, b);
  }
  return a;
}
template <typename T>
string NumberToString(T Number) {
  ostringstream second;
  second << Number;
  return second.str();
}
inline int nxt() {
  int aaa;
  scanf("%d", &aaa);
  return aaa;
}
inline long long int lxt() {
  long long int aaa;
  scanf("%lld", &aaa);
  return aaa;
}
inline double dxt() {
  double aaa;
  scanf("%lf", &aaa);
  return aaa;
}
template <class T>
inline T bigmod(T p, T e, T m) {
  T ret = 1;
  for (; e > 0; e >>= 1) {
    if (e & 1) ret = (ret * p) % m;
    p = (p * p) % m;
  }
  return (T)ret;
}
pair<long long int, long long int> ar[200010];
bool cmp(pair<long long int, long long int> a,
         pair<long long int, long long int> b) {
  return a.second > b.second;
}
int main() {
  int n = nxt();
  long long int h = lxt();
  for (int i = 1; i <= n; i++) {
    ar[i].first = lxt();
    ar[i].second = lxt();
  }
  sort(ar + 1, ar + n + 1);
  long long int cnt = 0;
  long long int mx = 0;
  for (int i = 1; i <= n; i++) {
    mx = max(mx, ar[i].first);
  }
  for (int i = 1; i <= n; i++) {
    if (ar[i].second >= mx) {
      h -= ar[i].second;
      cnt++;
      if (h <= 0) break;
    }
  }
  if (h < 0) h = 0;
  cnt += h / mx;
  h %= mx;
  if (h) cnt++;
  cout << cnt << endl;
  return 0;
}
