#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, h, nw, katanas;
  cin >> n >> h;
  int w[n], t[n], st = 0, nt = 0, lw = 0;
  for (int i = 0; i < n; i++) {
    cin >> w[i] >> t[i];
    if (w[i] > lw) lw = w[i];
  }
  for (int i = 0; i < n; i++) {
    if (t[i] >= lw && st < h) {
      st += t[i];
      nt++;
    }
  }
  if (st >= h) {
    cout << nt;
  } else {
    nw = (h - st) / lw;
    katanas = nw + nt;
    if (nw * lw + st >= h)
      cout << katanas;
    else
      cout << katanas + 1;
  }
  return 0;
}
