diff --git a/homework1/test1.cpp b/homework1/test1.cpp
index f0e6b2c..6ac12db 100644
--- a/homework1/test1.cpp
+++ b/homework1/test1.cpp
@@ -4,25 +4,30 @@
 using namespace std;
 
 typedef struct book {
-    string no;
+    string id;
     string name;
     double price;
 } book;
 
-int main() {
-    book books[100];
-    int i = 0;
-
-    // input
-    for (i; true; i++) {
-        cin >> books[i].no >> books[i].name >> books[i].price;
-        if (books[i].no == "0" && books[i].name == "0" && books[i].price == 0) {
-            break;
+int input(book *books) {
+    int length = 0;
+    for (int length = 0; true; length++) {
+        cin >> books[length].id >> books[length].name >> books[length].price;
+        if (books[length].id == "0" && books[length].name == "0" && books[length].price == 0) {
+            return length;
         }
     }
-    // output
-    cout << i << endl;
-    for (int j = 0; j < i; j++) {
-        cout << books[j].no << "\t" << books[j].name << "\t" << fixed << setprecision(2) << books[j].price << endl;
+}
+
+int output(book *books, int length) {
+    for (int i = 0; i < length; i++) {
+        cout << books[i].id << "\t" << books[i].name << "\t" << fixed << setprecision(2) << books[i].price << endl;
     }
 }
+
+int main() {
+    book books[100];
+    int length = input(books);
+    output(books, length);
+    return 0;
+}