import java.util.*;

class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int n = in.nextInt();

        int sum = 0;
        for(int i = 0; i < n; i++) {
            String sleeptime = in.next();
            String waketime = in.next();

            int k_1 = sleeptime.indexOf(":");
            int k_2 = waketime.indexOf(":");

            int h_sleep = Integer.valueOf(sleeptime.substring(0, k_1));
            int m_sleep = Integer.valueOf(sleeptime.substring(k_1+1, sleeptime.length()));
            int h_wake = Integer.valueOf(waketime.substring(0, k_2));
            int m_wake = Integer.valueOf(waketime.substring(k_2+1, waketime.length()));

            sum += h_wake * 60;
            sum += m_wake;

            if(h_wake - h_sleep < 0) {
                sum += (24 - h_sleep - 1) * 60;
                sum += 60 - m_sleep;
            } else {
                sum -= h_sleep * 60;
                sum -= m_sleep;
            }

            System.out.println(sum);
        }

        System.out.println(sum);
    }
}