first commit

J01002 - TÍNH TỔNG.java

@@ -0,0 +1,14 @@
+import java.util.Scanner;
+
+public class Main {
+    public static void main(String[] args) {
+        Scanner reader = new Scanner(System.in);
+        int t = reader.nextInt();
+        while(t>0){
+            t--;
+            Long n = reader.nextLong();
+            System.out.println(n*(n+1)/2);
+        }
+        reader.close();
+    }
+}