diff --git a/SS2301-02/ss2301_02.cpp b/SS2301-02/ss2301_02.cpp
index e69de29..6828690 100644
--- a/SS2301-02/ss2301_02.cpp
+++ b/SS2301-02/ss2301_02.cpp
@@ -0,0 +1,50 @@
+#include <iostream>
+#include <string>
+#include <sstream>
+#include <set>
+
+const std::set<std::string> LOWERCASE_WORDS = {
+    "a", "an", "and", "the", "in", "on", "at", "by", "for", 
+    "with", "about", "against", "between", "into", "through", 
+    "during", "before", "after"
+};
+
+std::string toLower(const std::string& str) {
+    std::string result = str;
+    for(char& c : result) {
+        c = std::tolower(c);
+    }
+    return result;
+}
+
+std::string capitalize(const std::string& input) {
+    std::stringstream ss(input);
+    std::string word, result;
+
+    bool isFirstWord = true;
+    while (ss >> word) {
+        if (!isFirstWord) {
+            result += " ";
+        }
+        if (isFirstWord || LOWERCASE_WORDS.find(toLower(word)) == LOWERCASE_WORDS.end()) {
+            word[0] = std::toupper(word[0]);
+            for (size_t i = 1; i < word.size(); ++i) {
+                word[i] = std::tolower(word[i]);
+            }
+        } else { // 追加
+            word = toLower(word);
+        }
+        result += word;
+        isFirstWord = false;
+    }
+
+    return result;
+}
+
+int main() {
+    std::string input = "C++ LANGUAGE IS A PROGRAMMING LANGUAGE.";
+    std::string output = capitalize(input);
+    std::cout << output << std::endl; // C++ Language Is a Programming Language.
+
+    return 0;
+}