diff --git a/04-fibonacci/index.js b/04-fibonacci/index.js
index 37c64cc..bbdc320 100644
--- a/04-fibonacci/index.js
+++ b/04-fibonacci/index.js
@@ -1,4 +1,5 @@
 export function fibonacci(value) {
   // implementar logica aqui
-  
+  var sqrt5 = Math.sqrt(5);
+  return Math.round(Math.pow(((1 + sqrt5) / 2), value) / sqrt5);
 }
\ No newline at end of file