diff --git a/2207/C语言同步练习源码/6-预处理-3.c b/2207/C语言同步练习源码/6-预处理-3.c
index 9886a8d..34b04f5 100644
--- a/2207/C语言同步练习源码/6-预处理-3.c
+++ b/2207/C语言同步练习源码/6-预处理-3.c
@@ -9,7 +9,7 @@ int main(){
     while(str[i] != '\0'){
         if(str[i] >= 'a' && str[i] <= 'y' || str[i] >= 'A' && str[i] <= 'Y' ){
             str[i]++;
-        }else{
+        }else if(str[i] == 'z' || str[i] == 'Z'){
             str[i]-=25;
         }
         i++;
diff --git a/2207/C语言同步练习答案.md b/2207/C语言同步练习答案.md
index f92831d..ec6a732 100644
--- a/2207/C语言同步练习答案.md
+++ b/2207/C语言同步练习答案.md
@@ -918,7 +918,7 @@ int main(){
     while(str[i] != '\0'){
         if(str[i] >= 'a' && str[i] <= 'y' || str[i] >= 'A' && str[i] <= 'Y' ){
             str[i]++;
-        }else{
+        }else if(str[i] == 'z' || str[i] == 'Z'){
             str[i]-=25;
         }
         i++;