diff --git a/04-fibonacci/index.js b/04-fibonacci/index.js
index 37c64cc..976c078 100644
--- a/04-fibonacci/index.js
+++ b/04-fibonacci/index.js
@@ -1,4 +1,17 @@
 export function fibonacci(value) {
   // implementar logica aqui
-  
+  let number1 = 0; 
+  let number2 = 1;     
+  let result;
+
+  if (value === 0 || value === 1 ) {
+    return value;
+  } else {
+    for  (let i = 1 ; i < value ; i++)  {
+      result = number2 + number1;
+      number1 = number2;
+      number2 = result;
+    }
+  }
+  return result;
 }
\ No newline at end of file