diff --git a/1.0/main.cpp b/1.0/main.cpp
index 560bb66..ebb47d7 100644
--- a/1.0/main.cpp
+++ b/1.0/main.cpp
@@ -1,4 +1,4 @@
-#include <siostream>
+#include <iostream>
 #include <cmath>
 
 double calculation(double numA, double numB, char oper)