diff --git a/src/AcTsExtension.ts b/src/AcTsExtension.ts
index 1608a96..f049241 100644
--- a/src/AcTsExtension.ts
+++ b/src/AcTsExtension.ts
@@ -428,10 +428,12 @@ class AcTsExtension {
                                 // read output
                                 const out = fs.readFileSync(that.tmptestoutfile).toString().trim().replace(/\n/g, "\r\n");
                                 fs.unlinkSync(that.tmptestoutfile);
-                                // read error
+                                if (out) {
+                                    that.channel.appendLine(out);
+                                }
+                                // check error
                                 const err = fs.readFileSync(that.tmptesterrfile).toString().trim().replace(/\n/g, "\r\n");
                                 fs.unlinkSync(that.tmptesterrfile);
-                                // check error
                                 if (err) {
                                     that.channel.appendLine(err);
                                     reject(`ERROR: error occurred`);
diff --git a/template/default_read.ts b/template/default_read.ts
index c597e46..05ebefd 100644
--- a/template/default_read.ts
+++ b/template/default_read.ts
@@ -1,6 +1,6 @@
 export { };
 // main
-async function main() {
+(async () => {
     // util for input
     const readline = require('readline').createInterface({ input: process.stdin });
     const readlineiter = readline[Symbol.asyncIterator]();
@@ -177,5 +177,4 @@ async function main() {
     // answer
     console.log(ans);
     return;
-}
-main();
+})();