#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, b, a = 0, cnt;
  int maxs = 0, maxt = 0;
  int sums = 0, sumt = 0;
  int ans;
  cin >> n >> b;
  cnt = 0;
  vector<int> s(n, 0);
  vector<int> t(n, 0);
  for (int i = 0; i < n; i++) {
    cin >> s[i] >> t[i];
    maxs = max(s[i], maxs);
    sumt += t[i];
  }
  sort(t.begin(), t.end());
  if (b < sumt) {
    while (b > a) {
      a += t[cnt];
      cnt++;
      ans++;
    }
    cout << ans << endl;
    return 0;
  }
  if (b > sumt) {
    b -= sumt;
    ans = (b + maxs - 1) / maxs + n;
    cout << ans << endl;
  }
  if (b == sumt) cout << n << endl;
  return 0;
}
