diff --git a/09-mostRepeatedChar/index.js b/09-mostRepeatedChar/index.js
index b113ed8..c9e5eb3 100644
--- a/09-mostRepeatedChar/index.js
+++ b/09-mostRepeatedChar/index.js
@@ -1,4 +1,18 @@
 export function mostUsedChar(text) {
     // implementar logica aqui
-    return ""
+    const tl = text.length;
+    const freq = {};
+    let maxFreq = 0;
+    let maxChar;
+    for (let i = 0; i < tl; ++i){
+        const isPair = (text.charCodeAt(i) & 0xF800) == 0xD800;
+        const c = isPair ? text.substr(i++, 2) : text[i];
+        const f = (freq[c] || 0) + 1;
+        freq[c] = f;
+        if (f > maxFreq){
+            maxFreq = f;
+            maxChar = c;
+        }
+    }
+    return maxChar
 }
\ No newline at end of file