#include <bits/stdc++.h>
long long int power(long long int a, long long int b) {
  long long int r = 1;
  for (; b; b >>= 1) {
    if (b & 1) r = r * a % 1000000007;
    a = a * a % 1000000007;
  }
  return r;
}
using namespace std;
int main() {
  ios::sync_with_stdio(false);
  cin.tie(NULL);
  long long int n, h;
  cin >> n >> h;
  vector<array<long long int, 2>> v;
  long long int ans = 0;
  for (int i = 0, j, k; i < n; i++) {
    cin >> j >> k;
    v.push_back({j, k});
  }
  sort(v.begin(), v.end(), greater<array<long long int, 2>>());
  int f = v[0][0];
  int cnt = 0;
  for (int i = 1; i < n; i++)
    if (f <= v[i][1] && ans < h) {
      cnt++;
      ans += v[i][1];
    }
  h -= ans;
  if (h <= 0)
    cout << cnt << endl;
  else {
    h -= v[0][1];
    cnt++;
    if (h <= 0)
      cout << cnt << endl;
    else {
      cnt += ceil(double(h) / f);
      cout << cnt << endl;
    }
  }
  return 0;
}
