#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using P = pair<int, int>;
typedef struct {
  int a;
  int b;
} Sord;
bool cmp(const Sord& x, const Sord& y) {
  if (x.a != y.a)
    return x.a < y.a;
  else {
    return x.b > y.b;
  }
}
int main() {
  int n, h;
  cin >> n >> h;
  vector<Sord> c(n);
  for (int i = 0; i < (n); i++) cin >> c[i].a >> c[i].b;
  sort(c.begin(), c.end(), cmp);
  int ca = c[n - 1].a, cb = c[n - 1].b;
  int mx = max(ca, cb);
  vector<int> cand;
  int ans = 0;
  for (int i = 0; i < (n - 1); i++) {
    if (c[i].b >= mx)
      h -= c[i].b, ans++;
    else if (ca < c[i].b)
      cand.push_back(c[i].b);
    if (h <= 0) {
      cout << ans;
      return 0;
    }
  }
  for (int i = 0; i < (cand.size()); i++) {
    if (h - mx <= 0) {
      ans++;
      cout << ans;
      return 0;
    }
    h -= cand[i];
    ans++;
  }
  if (h - cb <= 0) {
    ans++;
    cout << ans;
    return 0;
  }
  if (ca < cb) {
    h -= cb;
    ans++;
  }
  int x = (h + ca - 1) / ca;
  cout << ans + x;
}
