#include <bits/stdc++.h>
using namespace std;
int N, H;
int A[100010], B[100010];
int main() {
  scanf("%d%d", &N, &H);
  for (int i = 0; i < N; i++) {
    scanf("%d%d", A + i, B + i);
  }
  sort(A, A + N);
  sort(B, B + N);
  int ans = 1001001001;
  int sum = 0;
  for (int i = 0; i <= N; i++) {
    ans = min(ans, (H - sum + A[N - 1] - 1) / A[N - 1] + i);
    sum += B[N - 1 - i];
  }
  printf("%d\n", ans);
  return 0;
}
