#include <bits/stdc++.h>
using namespace std;
const long long MOD = 1e9 + 7;
const long long N = 2e5 + 10;
long long a[N], b[N];
int32_t main() {
  long long n, m;
  cin >> n >> m;
  long long mx = 0;
  long long sum = 0;
  for (long long i = 1; i <= n; i++) {
    cin >> a[i] >> b[i];
    mx = max(mx, a[i]);
  }
  long long cnt = 0;
  for (long long i = 1; i <= n; i++) {
    if (mx <= b[i]) {
      sum += b[i];
      cnt++;
    }
  }
  if (sum >= m) {
    cout << cnt << endl;
    return 0;
  } else {
    cout << cnt + ((m - sum) / mx) + (((m - sum) % mx) != 0) << endl;
    ;
  }
}
