#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using P = pair<int, int>;
const int INF = 1e9;
const int MOD = 1e9 + 7;
int dx[] = {1, 0, -1, 0, 1, -1, -1, 1};
int dy[] = {0, 1, 0, -1, 1, 1, -1, -1};
int main() {
  int N, H;
  cin >> N >> H;
  int a[N], b[N];
  for (int i = 0; i < N; i++) cin >> a[i] >> b[i];
  int maxi = 0;
  int max_idx = 0;
  for (int i = 0; i < N; i++) {
    if (maxi < a[i]) {
      maxi = a[i];
      max_idx = i;
    }
  }
  vector<int> v;
  for (int i = 0; i < N; i++)
    if (i != max_idx) {
      v.push_back(b[i]);
    }
  sort(v.begin(), v.end());
  int ans = 0;
  for (int i = v.size() - 1; i >= 0; i--) {
    if (maxi > v[i]) break;
    H -= v[i];
    ans++;
    if (H <= 0) break;
  }
  if (H - b[max_idx] > 0) {
    H -= b[max_idx];
    ans += (H + maxi - 1) / maxi;
  }
  cout << ans + 1 << endl;
  return 0;
}
