#include <bits/stdc++.h>
using namespace std;
long long n, h, ma = 0;
map<long long, long long> mp;
long long d[200010];
signed main() {
  cin >> n >> h;
  for (long long i = 0; i < n; i++) {
    long long a, b;
    cin >> a >> b;
    mp[a] = (long long)50000000000000000;
    mp[b] = 1;
    d[i * 2] = a;
    d[i * 2 + 1] = b;
  }
  sort(d, d + n * 2);
  reverse(d, d + n * 2);
  long long cnt = 0;
  for (long long i = 0; i < n * 2; i++) {
    if (mp[d[i]] == (long long)50000000000000000) {
      if (h % d[i] != 0) {
        cout << cnt + h / d[i] + 1 << endl;
      } else {
        cout << cnt + h / d[i] << endl;
      }
      break;
    } else {
      if (h <= d[i]) {
        cout << cnt << endl;
        break;
      } else {
        h -= d[i];
        cnt++;
      }
    }
  }
}
