diff --git a/main.mjs b/main.mjs
index 18d0717..f89b8a6 100644
--- a/main.mjs
+++ b/main.mjs
@@ -1,4 +1,7 @@
 import { argv } from 'node:process';
+import { env } from 'node:process';
+
+const DEBUG =  Boolean(env.DEBUG);
 
 const grades = [
 	{
@@ -31,13 +34,13 @@ function getGrade(mark){
 	if (typeof(mark) != 'number')
 	for (let i=0;i<=grades.length-1;i++){
 		const {max} = grades[i]
-		console.log({i,max})
+		printdebug({i,max})
 
 		if (max > mark) continue
 
 		for (let j=i;j>0;j--) {
 			const {min,grade} = grades[j]
-		console.log({j,min})
+		printdebug({j,min})
 			if (mark < min) continue
 			return grade
 		}
@@ -50,3 +53,9 @@ function getGrade(mark){
 
 const grade = getGrade(argv[2])
 console.log(grade)
+
+function printdebug(text) {
+	if (DEBUG) {
+		console.error('DEBUG:',text)
+	}
+}