#include <bits/stdc++.h>
using namespace std;
template <class T>
inline T GCD(T a, T b) {
  return b ? GCD(b, a % b) : a;
}
template <class T>
inline T LCM(T a, T b) {
  if (a < 0) return LCM(-a, b);
  if (b < 0) return LCM(a, -b);
  return a * (b / GCD(a, b));
}
int main() {
  int n, s;
  cin >> n >> s;
  int dol[n];
  int cent[n];
  int sweet = 0;
  int y = 0;
  int flag = 0;
  for (int i = 0; i < n; i++) {
    cin >> dol[i] >> cent[i];
    if (cent[i] != 0)
      sweet = 100 - cent[i];
    else
      sweet = 0;
    if (dol[i] < s || (dol[i] == s && cent[i] == 0)) {
      flag = 1;
      if (y < sweet) {
        y = sweet;
      }
    }
  }
  if (flag == 0)
    cout << "-1" << endl;
  else
    cout << y << endl;
  return 0;
}
