#include <bits/stdc++.h>
using namespace std;
int main() {
  long long N;
  long long H;
  cin >> N >> H;
  vector<long long> a(N);
  vector<long long> b(N);
  for (long long i = 0; i < N; i++) {
    cin >> a[i] >> b[i];
  }
  long long mmax = *max_element(a.begin(), a.end());
  sort(b.begin(), b.end());
  long long ff = 0;
  long long tmpc = 0;
  long long tmpd = 0;
  for (long long i = 0; i < N; i++) {
    if (tmpd >= H) {
      ff = 1;
      break;
    }
    tmpc++;
    if (b[i] > mmax) {
      tmpd += b[i];
    } else {
      tmpd += mmax;
    }
  }
  if (tmpd >= H) {
    ff = 1;
  }
  if (ff == 1) {
    cout << tmpc << endl;
    return 0;
  }
  long long dd = H - tmpd;
  long long cc = (dd / mmax);
  if (dd % mmax != 0) {
    cc++;
  }
  cout << tmpc + cc << endl;
}
