#include <bits/stdc++.h>
using namespace std;
int a[100000], b[100000];
int main() {
  int n, h, i, j = 0, max = 0, pos, s = 0;
  scanf("%d %d", &n, &h);
  for (i = 0; i < n; i++) {
    scanf("%d %d", &a[i], &b[i]);
    if (a[i] > max) {
      max = a[i];
      pos = i;
    }
    s += b[i];
    j++;
  }
  j--;
  s -= b[pos];
  j--;
  h -= s;
  while (h > 0) {
    h -= a[pos];
    j++;
  }
  printf("%d", j);
  return 0;
}
