diff --git a/math/double_factorial.cpp b/math/double_factorial.cpp
index 5f41337f2..3dd3e4a31 100644
--- a/math/double_factorial.cpp
+++ b/math/double_factorial.cpp
@@ -2,13 +2,15 @@
 #include <cassert>
 
 /* Double factorial of a non-negative integer n,
-is defined as the product of all the integers from 1 to n
+is defined as the product of 
+all the integers from 1 to n
 that have the same parity (odd or even) as n.
-It is also called as semifactorial of a number and is denoted by !! */
+It is also called as semifactorial 
+of a number and is denoted by !! */
 
 unsigned long long double_factorial_iterative(unsigned int n){
   unsigned long long res = 1;
-  for(unsigned long long i = n; i >= 0; i -= 2){
+  for( unsigned long long i = n; i >= 0; i -= 2 ){
     if(i == 0 || i == 1) return res;
     res *= i;
   }