diff --git a/extern/Makefile b/extern/Makefile
new file mode 100644
index 0000000..49ff7ba
--- /dev/null
+++ b/extern/Makefile
@@ -0,0 +1,22 @@
+CC = gcc
+CFLAGS = -Wall -MMD 
+LDFLAGS = -lm
+SRCS = $(wildcard *.c)
+OBJS = $(SRCS:.c=.o)
+DEPS = $(OBJS:.o=.d)
+TARGET = a.out
+
+all: $(TARGET)
+
+$(TARGET): $(OBJS)
+	$(CC) $(CFLAGS) -o $@ $^ $(LDFLAGS) 
+
+-include $(DEPS)
+
+%.o: %.c
+	$(CC) $(CFLAGS) -c $< -o $@ $(LDFLAGS)
+
+clean:
+	rm -f $(OBJS) $(DEPS) $(TARGET)
+
+
diff --git a/extern/p.c b/extern/p.c
index 9a3a353..fce8568 100644
--- a/extern/p.c
+++ b/extern/p.c
@@ -1,8 +1,8 @@
 // gcc p.c q.c -lm でビルド
 // ./a.out で実行
 
-#include "q.h"
 #include <stdio.h>
+#include "q.h"
 
 int main(){
   float d = 1.23;