Update README_EN.md

Author: yanglbme

solution/1200-1299/1220.Count Vowels Permutation/README_EN.md

@@ -215,37 +215,29 @@ class Solution {
 }
 ```
 
-```Java(Optimized with O(n) Time Complexity and O(1) Space)
+```java
 class Solution {
-    private final int mod = (int) 1e9 + 7;
-
     public int countVowelPermutation(int n) {
-        final int MOD = 1000000007;
-
+        final int mod = 1000000007;
         long countA = 1, countE = 1, countI = 1, countO = 1, countU = 1;
-
         for (int length = 1; length < n; length++) {
             // Calculate the next counts for each vowel based on the previous counts
             long nextCountA = countE;
-            long nextCountE = (countA + countI) % MOD;
-            long nextCountI = (countA + countE + countO + countU) % MOD;
-            long nextCountO = (countI + countU) % MOD;
+            long nextCountE = (countA + countI) % mod;
+            long nextCountI = (countA + countE + countO + countU) % mod;
+            long nextCountO = (countI + countU) % mod;
             long nextCountU = countA;
-
             // Update the counts with the newly calculated values for the next length
             countA = nextCountA;
             countE = nextCountE;
             countI = nextCountI;
             countO = nextCountO;
             countU = nextCountU;
         }
-
         // Calculate the total count of valid strings for length n
-        long totalCount = (countA + countE + countI + countO + countU) % MOD;
-
+        long totalCount = (countA + countE + countI + countO + countU) % mod;
         return (int) totalCount;
     }
-
 }
 ```