#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<ll, bool> plb;
const ll M = 1000000007;
plb a[2 * 100000];
bool cmp(plb a, plb b) {
  if (a.first != b.first)
    return a.first > b.first;
  else
    return !(b.second && !a.second);
}
int main() {
  int n;
  ll h;
  scanf("%d %lld", &n, &h);
  for (int i = 0; i < n; ++i) {
    ll x, y;
    scanf("%lld %lld", &x, &y);
    a[2 * i].first = x;
    a[2 * i].second = true;
    a[2 * i + 1].first = y;
    a[2 * i + 1].second = false;
  }
  sort(a, a + 2 * n, cmp);
  ll ans = 0;
  for (int i = 0; i < 2 * n && h >= 0; ++i) {
    if (a[i].second) {
      ans += h / a[i].first;
      if (h % a[i].first != 0) ++ans;
      break;
    } else {
      ++ans;
      h -= a[i].first;
    }
  }
  printf("%lld\n", ans);
}
