foo.cc:1:1: error: 'import' does not name a type; did you mean 'short'?
 import java.io.File;
 ^~~~~~
 short
foo.cc:2:1: error: 'import' does not name a type; did you mean 'short'?
 import java.io.FileReader;
 ^~~~~~
 short
foo.cc:3:1: error: 'import' does not name a type; did you mean 'short'?
 import java.io.IOException;
 ^~~~~~
 short
foo.cc:4:1: error: 'import' does not name a type; did you mean 'short'?
 import java.util.ArrayList;
 ^~~~~~
 short
foo.cc:5:1: error: 'import' does not name a type; did you mean 'short'?
 import java.util.HashMap;
 ^~~~~~
 short
foo.cc:6:1: error: 'import' does not name a type; did you mean 'short'?
 import java.util.Scanner;
 ^~~~~~
 short
foo.cc:8:1: error: expected unqualified-id before 'public'
 public class Main {
 ^~~~~~

自豪的采用HydroJudge(https://github.com/hydro-dev/Hydro)进行评测。