#include <bits/stdc++.h>
using namespace std;
const long long inf = 1e9 + 7;
const int N = 3e5 + 10;
int a[N];
int b[N];
long long solve(long long x, int n) {
  long long tmp = 0;
  for (int i = 1; i <= n; i++) {
    tmp += a[i] * x / b[i];
  }
  return tmp + n;
}
int main() {
  int n, c;
  cin >> n >> c;
  for (int i = 1; i <= n; i++) cin >> a[i] >> b[i];
  int l = 1, r = inf;
  int lans = inf, rans = 0;
  while (l <= r) {
    int mid = (l + r) / 2;
    if (solve(mid, n) >= c)
      lans = mid, r = mid - 1;
    else
      l = mid + 1;
  }
  l = 1, r = inf;
  while (l <= r) {
    int mid = (l + r) / 2;
    if (solve(mid, n) <= c)
      rans = mid, l = mid + 1;
    else
      r = mid - 1;
  }
  if (solve(lans, n) != c || solve(rans, n) != c)
    cout << 0 << endl;
  else
    cout << max(0, rans - lans + 1) << endl;
  return 0;
}
