#include <bits/stdc++.h>
using namespace std;
void init() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
}
const int N = 1e5 + 34;
pair<int, int> a[N];
void solve() {
  int n, h;
  scanf("%d%d", &n, &h);
  int m = -1;
  for (int i = 0; i < n; ++i) {
    scanf("%d%d", &a[i].second, &a[i].first);
    m = max(m, a[i].second);
  }
  sort(a, a + n, greater<pair<int, int>>());
  long long tot = 0;
  int ans = 2e9;
  for (int i = 0; i <= n; ++i) {
    int x = h - tot;
    ans = min(ans, i + (x + m - 1) / m);
    if (i == n) break;
    tot += a[i].first;
  }
  printf("%d", ans);
}
int main() {
  init();
  int t = 1;
  while (t--) {
    solve();
  }
  return 0;
}
