diff --git a/Strassen.java b/Strassen.java
index e2802ab..c932cff 100644
--- a/Strassen.java
+++ b/Strassen.java
@@ -38,7 +38,7 @@ public  static int[][] multiply(int a[][],int b[][])
 			int s6[][]=add(b11,b22);
 			int s7[][]=sub(a12,a22);
 			int s8[][]=add(b21,b22);
-			int s9[][]=sub(a11,a21);
+			int s9[][]=sub(a21,a11);
 			int s10[][]=add(b11,b12);
 			
 			int p1[][]=multiply(a11,s1);
@@ -130,4 +130,4 @@ public static void main(String ar[])
 			 
          			 
 	  }
-}
\ No newline at end of file
+}