Java 11
import java.io.*;
import java.util.StringTokenizer;
public class Main {
public static void main(String[] args) throws IOException {
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
int a = Integer.parseInt(br.readLine());
StringTokenizer st;
for (int i=1; i<=a; i++) {
st = new StringTokenizer(br.readLine(), " ");
bw.write("Case #"+i+": ");
bw.write(Integer.parseInt(st.nextToken()) + Integer.parseInt(st.nextToken()) + "\n");
}
br.close();
bw.flush();
bw.close();
}
}