#include <bits/stdc++.h>
#pragma comment(linker, "/stack:200000000")
#pragma GCC optimize("Ofast")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
using namespace std;
int64_t mod = 1e9 + 7;
int64_t mod1 = 1e9 + 5;
int64_t power(int64_t a, int64_t b) {
  if (b == 0)
    return 1;
  else if (b % 2 == 0)
    return power((((a % mod) * (a % mod)) % mod), b / 2) % mod;
  else
    return ((a % mod) * (power((((a % mod) * (a % mod)) % mod), b / 2) % mod)) %
           mod;
}
int64_t n, m, t;
vector<pair<int64_t, int64_t>> mat[5001];
vector<pair<int64_t, int64_t>> ulta[5001];
int32_t main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  int64_t n, h;
  cin >> n >> h;
  vector<pair<int64_t, int64_t>> v;
  for (int64_t i = 0; i < n; ++i) {
    int64_t a, b;
    cin >> a >> b;
    v.push_back({a, b});
  }
  sort(v.begin(), v.end());
  if (v[n - 1].second >= h) {
    cout << 1;
    return 0;
  }
  vector<pair<int64_t, int64_t>> v1;
  for (int64_t i = 0; i < v.size() - 1; ++i) {
    v1.push_back({v[i].second, v[i].first});
  }
  sort(v1.begin(), v1.end());
  int64_t cost = 0;
  for (int64_t i = v1.size() - 1; i >= 0; --i) {
    if (h <= v[n - 1].second) {
      cost++;
      cout << cost;
      return 0;
    }
    if (v1[i].first > v[n - 1].first) {
      h -= v1[i].first;
      cost++;
      if (h <= 0) break;
    }
  }
  if (h <= 0) {
    cout << cost;
    return 0;
  }
  if (v[n - 1].first >= v[n - 1].second) {
    cout << cost + (h + v[n - 1].first - 1) / v[n - 1].first;
    return 0;
  } else {
    cost++;
    h -= v[n - 1].second;
    cout << cost + (h + v[n - 1].first - 1) / v[n - 1].first;
  }
}
