diff --git a/04-fibonacci/index.js b/04-fibonacci/index.js
index 37c64cc..eae7c30 100644
--- a/04-fibonacci/index.js
+++ b/04-fibonacci/index.js
@@ -1,4 +1,11 @@
 export function fibonacci(value) {
   // implementar logica aqui
-  
+  let a = 0, b = 1, c = value;
+
+  for (let i = 2; i <= value; i++) {
+      c = a + b;
+      a = b;
+      b = c;
+  }
+  return c;
 }
\ No newline at end of file