import java.io.*;

public class Main {    
    static BufferedReader stdin
            = new BufferedReader(new InputStreamReader(System.in));

    static int T;
    static long N;
    static long M;
    static long[] res;

    public static void main(String[] args) throws Exception {   
        T = Integer.parseInt(stdin.readLine());
        res = new long[T];
        for(int t = 0; t < T; t++) {
            String[] tmp = stdin.readLine().split(" ");
            N = Long.parseLong(tmp[0]);
            M = Long.parseLong(tmp[1]);
            res[t] = solve();
        }
        for(long r : res)
            System.out.println(r);
    }

    static long solve() throws Exception {
        int T = (int)((double) M / N * 100) + 1;    // target

        // impossible to reach
        if(T == 100 || T == 101)
            return -1;

        // 100 * (M + n) / (N + n) >= T
        //      becomes n >= (T * N - 100 * M) / (100 - T)
        double n = (double)(T * N - 100 * M) / (100 - T);
        // Math.ceil to make as an integer
        long numWin = (long)Math.ceil(n);

        if(numWin <= 0 || numWin > 2000000000)
            return -1;

        // just in case ......
        for(int i = -500; i <= 500; i++) {
            if(numWin + i > 0) {
                int curr 
                        = (int)((double)(M + numWin + i) 
                                / (N + numWin + i) * 100);
                if(curr >= T)
                    return numWin + i;
            }
        }

        return numWin;
    }
}