#include <bits/stdc++.h>
#pragma GCC optimize(3)
using namespace std;
bool Finish_read;
template <class T>
inline void read(T &x) {
  Finish_read = 0;
  x = 0;
  int f = 1;
  char ch = getchar();
  while (!isdigit(ch)) {
    if (ch == '-') f = -1;
    if (ch == EOF) return;
    ch = getchar();
  }
  while (isdigit(ch)) x = x * 10 + ch - '0', ch = getchar();
  x *= f;
  Finish_read = 1;
}
template <class T>
inline void print(T x) {
  if (x / 10 != 0) print(x / 10);
  putchar(x % 10 + '0');
}
template <class T>
inline void writeln(T x) {
  if (x < 0) putchar('-');
  x = abs(x);
  print(x);
  putchar('\n');
}
template <class T>
inline void write(T x) {
  if (x < 0) putchar('-');
  x = abs(x);
  print(x);
}
struct node {
  long long atk, bom;
  inline bool operator<(const node &rhs) const { return bom > rhs.bom; }
} p[100010];
long long n, hp, ans, mx;
int main() {
  read(n);
  read(hp);
  for (int i = 1; i <= n; i++) {
    read(p[i].atk);
    read(p[i].bom);
  }
  sort(p + 1, p + n + 1);
  for (int i = 1; i < n; i++) {
    mx = max(mx, p[i].atk);
    if (mx >= p[i].bom) {
      printf("%lld\n", ans + hp / mx + (hp % mx != 0));
      return 0;
    }
    hp -= p[i].bom;
    ans++;
    if (hp <= 0) {
      printf("%lld\n", ans);
      return 0;
    }
  }
  int tmp = hp - p[n].bom;
  if (tmp <= 0)
    printf("%lld\n", ans + 1);
  else
    printf("%lld\n", ans + tmp / p[n].atk + (tmp % p[n].atk != 0) + 1);
}
