#include <bits/stdc++.h>
using namespace std;
inline int toInt(string s) {
  int v;
  istringstream sin(s);
  sin >> v;
  return v;
}
const int MOD = (int)1e9 + 7;
const int INF = (int)1e9;
const int dx[] = {0, 1, 0, -1};
const int dy[] = {1, 0, -1, 0};
const int ddx[] = {0, 1, 1, 1, 0, -1, -1, -1};
const int ddy[] = {1, 1, 0, -1, -1, -1, 0, 1};
int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int N, H;
  cin >> N >> H;
  vector<int> a(N), b(N);
  for (int i = 0; i < (int)(N); i++) cin >> a[i] >> b[i];
  sort(a.begin(), a.end(), greater<int>());
  sort(b.begin(), b.end(), greater<int>());
  int ans = 0;
  int used = 0;
  while (a[0] < b[used] && 0 < H && used < N) {
    H -= b[used];
    ans++;
    used++;
  }
  if (0 < H) ans += (double)H / a[0] + 0.9;
  cout << ans << endl;
  return 0;
}
