diff --git a/SS2301-02/ss2301_02.cpp b/SS2301-02/ss2301_02.cpp
index 6828690..87196ca 100644
--- a/SS2301-02/ss2301_02.cpp
+++ b/SS2301-02/ss2301_02.cpp
@@ -2,6 +2,7 @@
 #include <string>
 #include <sstream>
 #include <set>
+#include <fstream>
 
 const std::set<std::string> LOWERCASE_WORDS = {
     "a", "an", "and", "the", "in", "on", "at", "by", "for", 
@@ -31,7 +32,7 @@
             for (size_t i = 1; i < word.size(); ++i) {
                 word[i] = std::tolower(word[i]);
             }
-        } else { // 追加
+        } else {
             word = toLower(word);
         }
         result += word;
@@ -41,10 +42,25 @@
     return result;
 }
 
-int main() {
-    std::string input = "C++ LANGUAGE IS A PROGRAMMING LANGUAGE.";
+int main(int argc, char* argv[]) {
+    std::string input;
+
+    // 引数が与えられた場合、それをファイル名として読み込む
+    if (argc == 2) {
+        std::ifstream file(argv[1]);
+        if (!file) {
+            std::cerr << "Error: Could not open file: " << argv[1] << std::endl;
+            return 1;
+        }
+        std::getline(file, input, '\0');  // ファイルの内容を全て読み込む
+        file.close();
+    } else {
+        std::cout << "Enter the text to capitalize (end with Enter): ";
+        std::getline(std::cin, input);
+    }
+
     std::string output = capitalize(input);
-    std::cout << output << std::endl; // C++ Language Is a Programming Language.
+    std::cout << output << std::endl;
 
     return 0;
 }