#include <bits/stdc++.h>
using namespace std;
int main() {
  int N, H;
  cin >> N >> H;
  int a[114514], b[114514];
  for (int i = 0; i < N; i++) {
    cin >> a[i] >> b[i];
  }
  sort(a, a + N, greater<int>());
  sort(b, b + N, greater<int>());
  int M = a[0];
  long long int c[114514];
  c[1] = b[0];
  for (int i = 1; i < N; i++) {
    c[i + 1] = c[i] + b[i];
  }
  int ans = 1000000000;
  for (int i = 0; i <= N; i++) {
    if (H - c[i] >= 0) {
      int kaisuu = i + (H - c[i] + M - 1) / M;
      ans = min(ans, kaisuu);
    }
  }
  cout << ans << endl;
}
