#include <cstdio>
#include <algorithm>
using namespace std;
int N, H, a[100001], b[100001], ans;
int main() {
  scanf("%d %d", &N, &H);
  for(int i = 1; i <= N; ++i) {
    scanf("%d %d", &a[i], &b[i]);
  }
  sort(a+1, a+N+1);
  sort(b+1, b+N+1);
  for(int i = N; i > 0; --i) {
    if(b[i] <= a[N]) break;
    H -= b[i]; ++ans;
    if(H <= 0) break;
  }
  while(H > 0) {
    H -= a[N]; ++ans;
  }
  printf("%d\n", ans);
}