Add CI

.github/workflows/make.yml

@@ -0,0 +1,16 @@
+name: check makefile
+
+on:
+  push:
+    branches: '*'
+  pull_request:
+    branches: '*'
+
+jobs:
+build:
+  runs-on: ubuntu-latest
+  steps:
+  - name: checkout repo
+    uses: actions/checkout@main
+  - name: build application
+    run: make all

src/Main.java

@@ -3,7 +3,7 @@
 import java.io.BufferedReader;
 import java.io.File;
 import java.io.FileReader;
-import java.io.IOException;
+import java.io.IOException
 import java.util.Arrays;
 import java.util.Objects;
 import javax.swing.*;