diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..214a64d
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,32 @@
+progs_sh := d01
+progs_py := d02 d04
+progs_go := d05
+
+progs := $(progs_sh) $(progs_py) $(progs_go)
+
+.PHONY: all
+all: $(addsuffix _ok.txt,$(progs))
+
+.PHONY: clean
+clean:
+	rm -f $(addsuffix _out.txt,$(progs)) $(progs_go)
+
+.PHONY: ok-%
+ok-%: %_out.txt
+	@cp -v $< $*_ok.txt
+
+%_ok.txt: %_out.txt
+	@test -f $@ || (echo $*:; cat $<)
+	@test -f $@ && (diff -u $@ $< && touch $@) || exit 0
+
+$(addsuffix _out.txt,$(progs_sh)): %_out.txt: %.sh
+	./$< $*_input.txt > $@
+
+$(addsuffix _out.txt,$(progs_py)): %_out.txt: %.py
+	./$< $*_input.txt > $@
+
+$(addsuffix _out.txt,$(progs_go)): %_out.txt: %
+	./$< $*_input.txt > $@
+
+$(progs_go): %: %.go
+	go build -o $@ $<
diff --git a/d01_ok.txt b/d01_ok.txt
new file mode 100644
index 0000000..4b7edcf
--- /dev/null
+++ b/d01_ok.txt
@@ -0,0 +1,2 @@
+56397
+55701
diff --git a/d02_ok.txt b/d02_ok.txt
new file mode 100644
index 0000000..033b7ad
--- /dev/null
+++ b/d02_ok.txt
@@ -0,0 +1,2 @@
+2169
+60948
diff --git a/d04_ok.txt b/d04_ok.txt
new file mode 100644
index 0000000..dec80b1
--- /dev/null
+++ b/d04_ok.txt
@@ -0,0 +1,2 @@
+26346
+8467762
diff --git a/d05_ok.txt b/d05_ok.txt
new file mode 100644
index 0000000..156521f
--- /dev/null
+++ b/d05_ok.txt
@@ -0,0 +1,2 @@
+579439039
+7873084