#include <bits/stdc++.h>
using namespace std;
const int INF = 1000000000;
int main() {
  int N;
  long long H;
  scanf("%d %lld", &N, &H);
  vector<long long> a(N), b(N);
  for (int i = 0; i < N; ++i) {
    scanf("%lld %lld", &a[i], &b[i]);
  }
  sort(b.begin(), b.end(), greater<long long>());
  long long wielding_max = *max_element(a.begin(), a.end());
  int ans = 0;
  for (int i = 0; i < N; ++i) {
    if (b[i] < wielding_max) {
      break;
    }
    if (H <= 0) {
      break;
    }
    H -= b[i];
    ++ans;
  }
  ans += ((H + wielding_max - 1) / wielding_max);
  printf("%d\n", ans);
  return 0;
}
