#include <bits/stdc++.h>
using namespace std;
const long long N = 1e10;
void solve() {
  long long n, c;
  cin >> n >> c;
  long long a[n], b[n];
  for (long long i = 0; i < n; i++) {
    cin >> a[i] >> b[i];
  }
  long long low = -1, high = -1;
  for (long long i = 1; i <= 100000; i++) {
    long long cnt = 0;
    for (long long j = 0; j < n; j++) {
      cnt++;
      cnt += (a[j] * i) / b[j];
    }
    if (cnt > c) break;
    if (cnt < c) continue;
    if (cnt == c) {
      if (low == -1) low = i;
      high = i;
    }
  }
  if (high == -1)
    cout << 0;
  else
    cout << high - low + 1;
}
int32_t main() {
  long long t = 1;
  while (t--) {
    solve();
  }
  return 0;
}
