diff --git a/src/isogram.c b/src/isogram.c
index fd0bdb3..a5bb01f 100644
--- a/src/isogram.c
+++ b/src/isogram.c
@@ -4,8 +4,25 @@
 #include <string.h>
 #include <stdio.h>
 
+char oldletter;
+char newletter;
+int count = 0;
+
 
 bool is_isogram(const char phrase[]){
 
+    wihle(phrase[count] != '\0'){
+        newletter = phrase[counter];
+
+        if (counter >= 1){
+            oldletter = phrase[counter -1];
+            if (newletter == oldletter){
+                printf("It`s not an isisogram!!");
+                return false;
+            }
+        }
+        count++;
+    }
+    printf("It`s an isisogram!!");
     return true;
 }