#include <bits/stdc++.h>
template <class T>
void read(T &);
template <class T>
void write(const T &);
typedef const long long &cll;
typedef const int &ci;
const int iinf = 2147483647;
const long long llinf = 9223372036854775807ll;
using std::abs;
using std::max;
using std::min;
const int N = 200005;
class Line {
 public:
  long long C, V, K;
  bool operator<(const Line i) const {
    return (C == i.C) ? (V < i.V) : (C < i.C);
  }
  long long operator()(const long long i) const { return (i - K + V - 1) / V; }
};
Line a[N];
int catchtime(int i, int j) { return (a[i].K - a[j].K) / (a[j].V - a[i].V); }
bool check(int i, int j, long long C) {
  long long iC = a[i](C), jC = a[j](C);
  if (iC != jC) {
    return iC > jC;
  }
  return a[i].K + iC * a[i].V <= a[j].K + jC * a[j].V;
}
int que[N], qh, qt;
int n;
long long S;
int main() {
  read(n), read(S);
  for (int i = 1; i <= n; ++i) {
    read(a[i].V), read(a[i].C);
  }
  std::sort(a + 1, a + n + 1);
  long long ans = llinf;
  qh = 1, qt = 0;
  int lasV = 0;
  for (int i = 1; i <= n; ++i) {
    if (a[i].V <= lasV) {
      continue;
    }
    lasV = a[i].V;
    while (qh < qt && check(que[qh], que[qh + 1], a[i].C)) {
      ++qh;
    }
    if (i != 1) {
      int j = que[qh];
      a[i].K = a[j].K - a[j](a[i].C) * (a[i].V - a[j].V) - a[i].C;
    }
    ans = min(ans, a[i](S));
    while (qh < qt &&
           catchtime(que[qt - 1], que[qt]) >= catchtime(que[qt], i)) {
      --qt;
    }
    que[++qt] = i;
  }
  write(ans), putchar('\n');
  return 0;
}
template <class T>
inline void read(T &Re) {
  T k = 0;
  char ch = getchar();
  int flag = 1;
  while (!(ch >= '0' && ch <= '9')) {
    if (ch == '-') {
      flag = -1;
    }
    ch = getchar();
  }
  while ((ch >= '0' && ch <= '9')) {
    k = (k << 1) + (k << 3) + ch - '0';
    ch = getchar();
  }
  Re = flag * k;
}
template <class T>
inline void write(const T &Wr) {
  if (Wr < 0) {
    putchar('-');
    write(-Wr);
  } else {
    if (Wr < 10) {
      putchar(Wr + '0');
    } else {
      write(Wr / 10);
      putchar((Wr % 10) + '0');
    }
  }
}
