diff --git a/pttodo/root.go b/pttodo/root.go
index c8bb814..ff7baee 100644
--- a/pttodo/root.go
+++ b/pttodo/root.go
@@ -13,6 +13,19 @@ type Root struct {
 	Done      []Todo
 }
 
+func NewRootFromFiles(p ...string) (Root, error) {
+	var result Root
+	for _, p := range p {
+		subroot, err := NewRootFromFile(p)
+		if err != nil {
+			return Root{}, err
+		}
+		result.MergeIn(subroot)
+	}
+	result.AutoMove()
+	return result, nil
+}
+
 func NewRootFromFile(p string) (Root, error) {
 	if b, err := os.ReadFile(p); err == nil && len(bytes.TrimSpace(b)) == 0 {
 		return Root{}, nil
diff --git a/pttodo/root_test.go b/pttodo/root_test.go
index 43f5c70..c72815b 100644
--- a/pttodo/root_test.go
+++ b/pttodo/root_test.go
@@ -233,3 +233,27 @@ func TestRootFromFile(t *testing.T) {
 		})
 	}
 }
+
+func TestRootFromFiles(t *testing.T) {
+	d := t.TempDir()
+	ps := []string{
+		path.Join(d, "a"),
+		path.Join(d, "b"),
+	}
+	os.WriteFile(ps[0], []byte(`["a"]`), os.ModePerm)
+	os.WriteFile(ps[1], []byte(`["b"]`), os.ModePerm)
+
+	got, err := NewRootFromFiles(ps...)
+	if err != nil {
+		t.Fatal(err)
+	}
+	want := Root{
+		Todo: []Todo{
+			{Todo: "a"},
+			{Todo: "b"},
+		},
+	}
+	if fmt.Sprintf("%+v", got) != fmt.Sprintf("%+v", want) {
+		t.Errorf("want\n\t%+v, got \n\t%+v", want, got)
+	}
+}