diff --git a/2_Grace/Grace b/2_Grace/Grace
new file mode 100755
index 0000000..994a32a
Binary files /dev/null and b/2_Grace/Grace differ
diff --git a/2_Grace/Grace.c b/2_Grace/Grace.c
new file mode 100644
index 0000000..70b4936
--- /dev/null
+++ b/2_Grace/Grace.c
@@ -0,0 +1,13 @@
+/*comment outside*/
+#include <stdio.h>
+
+char *second_function() {
+	return "/*comment outside*/%c#include <stdio.h>%c%cchar *second_function() {%c	return %c%s%c;%c}%c%cint main() {%c	/*comment inside*/%c	char *program = second_function();%c	printf(program, 10, 10, 10, 10, 34, program, 34, 10, 10, 10, 10, 10, 10, 10, 10, 10);%c	return 0;%c}%c";
+}
+
+int main() {
+	/*comment inside*/
+	char *program = second_function();
+	printf(program, 10, 10, 10, 10, 34, program, 34, 10, 10, 10, 10, 10, 10, 10, 10, 10);
+	return 0;
+}
diff --git a/2_Grace/Makefile b/2_Grace/Makefile
new file mode 100644
index 0000000..0666438
--- /dev/null
+++ b/2_Grace/Makefile
@@ -0,0 +1,111 @@
+# - - - - - - #
+#             #
+#   COLORS    #
+#             #
+# - - - - - - #
+
+GRAY     = "\e[0;30m"
+RED      = "\e[0;31m"
+GREEN    = "\e[0;32m"
+YELLOW   = "\e[0;33m"
+BLUE     = "\e[0;34m"
+PURPLE   = "\e[0;35m"
+CYAN     = "\e[0;36m"
+WHITE    = "\e[0;37m"
+
+B_GRAY   = "\e[1;30m"
+B_RED    = "\e[1;31m"
+B_GREEN  = "\e[1;32m"
+B_YELLOW = "\e[1;33m"
+B_BLUE   = "\e[1;34m"
+B_PURPLE = "\e[1;35m"
+B_CYAN   = "\e[1;36m"
+B_WHITE  = "\e[1;37m"
+
+RESET    = "\e[0m"
+
+# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - #
+#               . name = value \          . += append to a variable   #
+#   VARIABLES   .        value            . != set result of command  #
+#               . name is case sensitive  . ?= set if not already set #
+# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - #
+
+
+NAME          = Grace
+
+CC            = clang
+EXT           = c
+
+CFLAGS        = -Wall -Wextra -Werror $(INCLUDES)
+CFLAGS       += -g3
+
+VPATH         = $(D_SRCS)
+
+LIBS          =
+
+F_INCLUDES    = $(HEADERS:%=$(D_HEADERS)/%)
+INCLUDES      = -I$(D_HEADERS)
+
+D_SRCS        = .
+SRCS          = Grace.c
+
+D_HEADERS     = .
+HEADERS       = 
+
+D_OBJS        = builds
+OBJS          = $(SRCS:%.$(EXT)=$(D_OBJS)/%.o)
+
+ifeq "$(D_OBJS)" "."
+  RM_OBJS     = rm -f $(OBJS)
+else
+  RM_OBJS     = rm -rf $(D_OBJS)
+endif
+
+
+# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - #
+#             .   target: prerequisites   .   $@ : target             #
+#    RULES    .           recipe          .   $< : 1st prerequisite   #
+#             .           recipe          .   $^ : all prerequisites  #
+# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - #
+
+all: $(NAME)
+
+# %.$(EXT) | $(D_OBJS) -> pipe is for order-only prerequisites :
+#  - for each file "%.$(EXT)" :
+#    - if it has been modified since last time
+#    - execute rules on corresponding target file "$(D_OBJS)/%.o"
+#  - and directory "$(D_OBJS)" is order-only prerequisite :
+#    - it must exist before executing rule
+#    - but last time modification is not checked
+$(D_OBJS)/%.o: %.$(EXT) | $(D_OBJS)
+	@echo $(CYAN)"compilation (objects.o) :"$(RESET)
+	$(CC) $(CFLAGS) -c $< -o $@
+
+$(D_OBJS):
+	mkdir $@
+
+$(OBJS): $(F_INCLUDES)
+
+$(NAME): $(OBJS)
+	@echo $(CYAN)"linkage (link objects.o) :"$(RESET)
+	$(CC) $(OBJS) -o $@ $(LIBS)
+
+leaks: $(NAME)
+	valgrind --leak-check=full --show-leak-kinds=all ./$(NAME)
+
+diff: $(NAME)
+	@echo $(CYAN)"compare source with output :"$(RESET)
+	./$(NAME) > tmp_$(NAME)
+	- diff --color --report-identical-files tmp_$(NAME) $(SRCS)
+	rm tmp_$(NAME)
+
+clean:
+	$(RM_OBJS)
+
+fclean: clean
+	rm -f $(NAME)
+
+re: fclean all
+
+.PHONY : all clean fclean re
+
diff --git a/2_Grace/builds/Grace.o b/2_Grace/builds/Grace.o
new file mode 100644
index 0000000..3ac5ab0
Binary files /dev/null and b/2_Grace/builds/Grace.o differ
diff --git a/Makefile b/Makefile
index c4c27b5..4194df4 100644
--- a/Makefile
+++ b/Makefile
@@ -30,7 +30,8 @@ RESET    = "\e[0m"
 #               . name is case sensitive  . ?= set if not already set #
 # - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - #
 
-D_QUINES  = ./1_Colleen
+D_QUINES  = ./1_Colleen \
+						./2_Grace
 
 # - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - #
 #             .   target: prerequisites   .   $@ : target             #
@@ -44,6 +45,12 @@ all: $(D_QUINES)
 		$(MAKE) -C $$dir; \
 	done
 
+diff: $(D_QUINES)
+	@for dir in $^; do \
+		echo $(B_CYAN)"diff $$dir"$(RESET); \
+		$(MAKE) diff -C $$dir; \
+	done
+
 clean: $(D_QUINES)
 	@for dir in $^; do \
 		echo $(B_YELLOW)"clean $$dir"$(RESET); \
diff --git a/README.md b/README.md
index 39af52c..6ebdfc8 100644
--- a/README.md
+++ b/README.md
@@ -1,29 +1 @@
-# README #
-
-This README would normally document whatever steps are necessary to get your application up and running.
-
-### What is this repository for? ###
-
-* Quick summary
-* Version
-* [Learn Markdown](https://bitbucket.org/tutorials/markdowndemo)
-
-### How do I get set up? ###
-
-* Summary of set up
-* Configuration
-* Dependencies
-* Database configuration
-* How to run tests
-* Deployment instructions
-
-### Contribution guidelines ###
-
-* Writing tests
-* Code review
-* Other guidelines
-
-### Who do I talk to? ###
-
-* Repo owner or admin
-* Other community or team contact
\ No newline at end of file
+# DR_QUINE
diff --git a/notes.md b/notes.md
new file mode 100644
index 0000000..b81016c
--- /dev/null
+++ b/notes.md
@@ -0,0 +1 @@
+- [interactions between MACRO and comments](https://gcc.gnu.org/onlinedocs/cpp/Stringizing.html#:~:text=the%20stringized%20result.-,Comments,-are%20replaced%20by)