#include <bits/stdc++.h>
using namespace std;
int vx[] = {0, 1, 0, -1};
int vy[] = {1, 0, -1, 0};
int dx[] = {1, 0, -1, 1, -1, 1, 0, -1};
int dy[] = {1, 1, 1, 0, 0, -1, -1, -1};
const long long mod = 1e9 + 7;
const int INF = INT_MAX / 2;
const int MAX = 1e9;
int main() {
  int n, h;
  cin >> n >> h;
  vector<int> a(n);
  vector<int> b(n);
  for (int i = 0; i < n; i++) cin >> a[i] >> b[i];
  int maxa = a[0];
  int idx = 0;
  for (int i = 0; i < n; i++) {
    if (maxa < a[i]) {
      maxa = a[i];
      idx = i;
    }
  }
  vector<int> select;
  for (int i = 0; i < n; i++) {
    if (b[i] >= a[idx]) {
      select.push_back(b[i]);
    }
  }
  sort(select.begin(), select.end(), greater<int>());
  int ans = 0;
  for (int i = 0; i < select.size(); i++) {
    if (h <= 0) {
      cout << ans << endl;
      return 0;
    } else if (h < b[idx]) {
      ans++;
      cout << ans << endl;
      return 0;
    } else {
      h -= b[i];
      ans++;
    }
  }
  if (h > 0) {
    ans += 1 + (h - b[idx]) / a[idx];
  }
  cout << ans << endl;
  return 0;
}
