diff --git a/tasks/rpn.cpp b/tasks/rpn.cpp
index c0c83f28f5d9a9d07b302e9f5e3d1e6e902d50a8..01b5d7e44ab2671be89a0bcd9e6f1378d9c08374 100644
--- a/tasks/rpn.cpp
+++ b/tasks/rpn.cpp
@@ -8,6 +8,9 @@
 
 std::string rpn_eval(std::string expr)
 {
+  int value = 0;
+
+  stack = new Stack();
 
   return expr;
 }
diff --git a/tasks/stack.cpp b/tasks/stack.cpp
index d3efc92a35e4fe9b2d0a62b7340904ab1ab53165..ff5d8cc634025388058e6038d5f78cf371943325 100644
--- a/tasks/stack.cpp
+++ b/tasks/stack.cpp
@@ -13,7 +13,7 @@ bool Stack::pop(int * value)
 {
     if(!empty())
     {
-        value = stacks_data[head_of_stack]
+        value = stacks_data[head_of_stack];
     }
     else
     {
@@ -33,7 +33,7 @@ bool Stack::empty() const
     }
     else
     {
-        return false
+        return false;
     }
 }