#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cmath>
#include <string>
#include <vector>
#include <queue>
#include <stack>
#include <algorithm>
#include <climits>
using namespace std;
typedef long long LL;


int x[200],y[200];
int main()
{
	int n,s;
	cin>>n>>s;
	for(int i=0;i<n;i++)
		cin>>x[i]>>y[i];
	s *= 100;
	int ans = -1;
	for(int i=0;i<n;i++) {
		if(s>=x[i]*100+y[i]) {
			int temp = (s - x[i]*100-y[i])%100;
			if(temp > ans) ans = temp;
		}
	}
	cout<<ans;
}