#include <bits/stdc++.h>
int main() {
  int n, h, temp[2];
  int a, b[10000];
  int count;
  int i, j, k;
  scanf("%d%d", &n, &h);
  for (i = 0; i < n; i++) {
    scanf("%d%d", &temp[0], &temp[1]);
    if (a < temp[0]) a = temp[0];
    for (j = 0; j < i; j++) {
      if (b[j] < temp[1]) break;
    }
    for (k = i - 1; k >= j; k--) b[k + 1] = b[k];
    b[j] = temp[1];
  }
  for (count = 0; (h > 0) && (b[count] > a); h -= b[count], count++)
    ;
  if (h % a == 0)
    count += h / a;
  else
    count += h / a + 1;
  printf("%d\n", count);
  return 0;
}
