#include <bits/stdc++.h>
int main() {
  int N, H, i, j;
  scanf("%d%d", &N, &H);
  int b[N];
  int tmp = 0, a = 0, num = 0, tmp2 = 0, n = 0;
  for (i = 0; i < N; i++) {
    scanf("%d%d", &tmp, &tmp2);
    if (tmp > a) a = tmp;
    if (tmp2 > a) {
      b[n] = tmp2;
      n++;
    }
  }
  for (i = 0; i < n - 1; i++) {
    for (j = 0; j < n - i - 1; j++) {
      if (b[j] < b[j + 1]) {
        tmp = b[j];
        b[j] = b[j + 1];
        b[j + 1] = tmp;
      }
    }
  }
  for (i = 0; i < n; i++) {
    if (b[i] <= a) {
      num += H / a + (H % a != 0);
      break;
    } else {
      num += 1;
      H -= b[i];
      if (i == n - 1 && H > 0) num += H / a + (H % a != 0);
    }
  }
  printf("%d\n", num);
}
