diff --git a/Chapter_1/io.cpp b/Chapter_1/io.cpp
new file mode 100644
index 0000000..50aa74a
--- /dev/null
+++ b/Chapter_1/io.cpp
@@ -0,0 +1,13 @@
+#include <iostream>
+
+int readNumber()
+{
+	int a = 0;
+	std::cin >> a;
+	return a;
+}
+
+void writeAnswer(int a)
+{
+	std::cout << a << std::endl;
+}
diff --git a/Chapter_1/io.hpp b/Chapter_1/io.hpp
new file mode 100644
index 0000000..d078fdc
--- /dev/null
+++ b/Chapter_1/io.hpp
@@ -0,0 +1,7 @@
+#ifndef IO_HPP_
+#define IO_HPP_
+
+int readNumber();
+void writeAnswer(int);
+
+#endif
diff --git a/Chapter_1/main.cpp b/Chapter_1/main.cpp
new file mode 100644
index 0000000..2c714b7
--- /dev/null
+++ b/Chapter_1/main.cpp
@@ -0,0 +1,13 @@
+#include "io.hpp"
+
+int main()
+{
+	int a = 0, b = 0;
+
+	a = readNumber();
+	b = readNumber();
+
+	writeAnswer(a + b);
+
+	return 0;
+}