#include <bits/stdc++.h>
using namespace std;
int N;
long long H;
vector<long long> A, B;
void solve() {
  sort(A.rbegin(), A.rend());
  sort(B.rbegin(), B.rend());
  vector<long long> cum(N + 1, 0);
  for (int i = 0; i < (N); ++i) cum[i + 1] = cum[i] + B[i];
  long long res = 1e9 + 100;
  for (int i = 0; i <= (N); ++i) {
    long long h = H - cum[i];
    long long x = i;
    x += (h + A.front() - 1) / A.front();
    res = min(res, x);
  }
  cout << res << endl;
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cin >> N >> H;
  A.resize(N), B.resize(N);
  for (int i = 0; i < (N); ++i) cin >> A[i] >> B[i];
  solve();
  return 0;
}
