diff --git a/04-fibonacci/index.js b/04-fibonacci/index.js
index 984c5e6..ad1783a 100644
--- a/04-fibonacci/index.js
+++ b/04-fibonacci/index.js
@@ -1,9 +1,19 @@
 export function fibonacci(value) {
   // implementar logica aqui
-  if(value < 2){
-    value = value;
-  }else{
-    value = fibonacci(value - 1) + fibonacci(value - 2);
+  if(value == 0){
+    return value;
   }
-  return value;
+  let firstValue = 0, secondValue = 1, thirdValue =1;
+  for(let i = 2; i <= value; i++){
+    thirdValue = firstValue + secondValue;
+    firstValue = secondValue;
+    secondValue = thirdValue;
+  }
+  return thirdValue;
+  // if(value < 2){
+  //   value = value;
+  // }else{
+  //   value = fibonacci(value - 1) + fibonacci(value - 2);
+  // }
+  // return value;
 }
\ No newline at end of file