#include <bits/stdc++.h>
using namespace std;
int main() {
  int ans = -1;
  int n, dol, cent, s, i;
  cin >> n >> s;
  for (i = 0; i < n; i++) {
    cin >> dol >> cent;
    if (s > dol && cent != 0 && 100 - cent > ans) ans = 100 - cent;
    if (s >= dol && cent == 0 && ans == -1) ans = 0;
  }
  cout << ans;
  return 0;
}
