#include <bits/stdc++.h>
using namespace std;
int main(int argc, char const *argv[]) {
  int n, h;
  cin >> n >> h;
  vector<int> a(n), b(n);
  vector<pair<int, int>> c(2 * n);
  for (long long i = (long long)(0); i < (long long)(n); ++i) {
    cin >> a[i] >> b[i];
    c[2 * i] = {a[i], 0};
    c[2 * i] = {b[i], 1};
  }
  sort(c.begin(), c.end(), greater<pair<int, int>>());
  int ans = 0;
  for (long long i = (long long)(0); i < (long long)(2 * n); ++i) {
    if (c[i].second == 0) {
      ans += (h + c[i].first - 1) / c[i].first;
      break;
    } else {
      ans += 1;
      h -= c[i].first;
    }
    if (h <= 0) {
      break;
    }
  }
  return 0;
}
