diff --git a/04-file-copying.c b/04-file-copying.c
new file mode 100644
index 0000000..5c7e6f2
--- /dev/null
+++ b/04-file-copying.c
@@ -0,0 +1,13 @@
+#include <stdio.h>
+
+/* copy input to output; 1st version */
+int main()
+{
+	int c;
+
+	c = getchar();
+	while (c != EOF) {
+		putchar(c);
+		c = getchar();
+	}
+}
diff --git a/Makefile b/Makefile
index 3fcaad8..e70c2c4 100644
--- a/Makefile
+++ b/Makefile
@@ -1,4 +1,4 @@
-all: hello mathvars c2f
+all: hello mathvars c2f input
 
 hello: 01-hello-world.c
 	gcc -o ./bin/01-helloworld 01-hello-world.c
@@ -9,5 +9,8 @@ mathvars: 02-vars-and-math.c
 c2f: 03-celsius-to-fahrenheit.c
 	gcc -o ./bin/03-c2f 03-celsius-to-fahrenheit.c
 
+input: 04-file-copying.c
+	gcc -o ./bin/04-input 04-file-copying.c
+
 clean:
 	$(RM) ./bin/*-*