#include <bits/stdc++.h>
using namespace std;
const int maxn = 1e5 + 5;
int a[maxn];
int b[maxn];
bool cmp(const int &a, const int &b) { return a > b; }
int main() {
  int N, H;
  while (~scanf("%d %d", &N, &H)) {
    int maxa = 0;
    for (int i = 1; i <= N; i++) {
      cin >> a[i] >> b[i];
      maxa = max(maxa, a[i]);
    }
    for (int i = 1; i <= N; i++) {
      if (b[i] < maxa) b[i] = 0;
    }
    sort(b + 1, b + N, cmp);
    int flag = 0;
    int cnt = 0;
    int sum = 0;
    for (int i = 1; i <= N; i++) {
      if (b[i] == 0) break;
      sum += b[i];
      cnt++;
      if (sum >= H) {
        flag = 1;
        break;
      }
    }
    if (flag)
      cout << cnt << endl;
    else {
      cnt += (H - sum) / maxa;
      if ((H - sum) % maxa != 0) {
        cnt++;
      }
      printf("%d\n", cnt);
    }
  }
  return 0;
}
