#include <bits/stdc++.h>
using namespace std;
void my_dbg() { cout << endl; }
template <typename Arg, typename... Args>
void my_dbg(Arg A, Args... B) {
  cout << ' ' << A;
  my_dbg(B...);
}
using ll = long long;
using vi = vector<int>;
using vl = vector<ll>;
const int inf = INT_MAX;
const int ninf = INT_MIN;
const int mod = 1e9 + 7;
const int N = 2e5 + 2;
void solve() {
  int n, h;
  scanf("%d", &n);
  scanf("%d", &h);
  pair<int, int> p[n];
  for (int i = (int)(0); i < (int)(n); i++) {
    scanf("%d", &p[i].first);
    scanf("%d", &p[i].second);
  }
  sort(p, p + n, greater<pair<int, int>>());
  int a_max = p[0].first, cnt = 0;
  for (int i = (int)(0); i < (int)(n); i++) {
    if (h <= 0) break;
    if (p[i].second > a_max) h -= p[i].second, cnt++;
  }
  while (h > 0) {
    h -= a_max;
    cnt++;
  }
  printf("%d\n", (int)(cnt));
}
int main() {
  int t = 1;
  while (t--) {
    solve();
  }
  return 0;
}
