diff --git a/data/CMakeLists.txt b/data/CMakeLists.txt
index 0432e9a..2410c31 100644
--- a/data/CMakeLists.txt
+++ b/data/CMakeLists.txt
@@ -1,6 +1,6 @@
 set(PROJECT_NAME ${CMAKE_PROJECT_NAME})
 set(CMAKE_CXX_STANDARD 17)
-set(CMAKE_CXX_FLAGS "-fsanitize=address -g")
+set(CMAKE_CXX_FLAGS "-O2 -pg")
 set(ENV{MAKEFLAGS} "-j16")
 include_directories(${PROJECT_SOURCE_DIR}/include)
 link_directories(${PROJECT_SOURCE_DIR}/src)
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 7267cb9..ae73419 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -1,5 +1,5 @@
 set(PROJECT_NAME ${CMAKE_PROJECT_NAME})
 set(CMAKE_CXX_STANDARD 17)
-set(CMAKE_CXX_FLAGS "-fsanitize=address -g")
+set(CMAKE_CXX_FLAGS "-O2 -pg")
 include_directories(${PROJECT_SOURCE_DIR}/include)
 add_library(int2048 STATIC int2048.cpp)
\ No newline at end of file
diff --git a/src/int2048.cpp b/src/int2048.cpp
index 9c2b985..ea80abd 100644
--- a/src/int2048.cpp
+++ b/src/int2048.cpp
@@ -750,9 +750,9 @@ inline void UnsignedDivide(int2048 &A, const int2048 *pB) {
       else
         store[tot][i] = 0;
     }
-    fprintf(stderr, "x: ");
-    for (int i = 0; i < blocks_of_x; i++) fprintf(stderr, "%08d ", x.val[i]);
-    fprintf(stderr, "\n");
+    // fprintf(stderr, "x: ");
+    // for (int i = 0; i < blocks_of_x; i++) fprintf(stderr, "%08d ", x.val[i]);
+    // fprintf(stderr, "\n");
   }
   delete[] store[0];
   delete[] store[1];