diff --git a/src/week4/BOJ14405/BOJ14405_V1.cpp b/src/week4/BOJ14405/BOJ14405_V1.cpp
new file mode 100644
index 0000000..58a3e4c
--- /dev/null
+++ b/src/week4/BOJ14405/BOJ14405_V1.cpp
@@ -0,0 +1,32 @@
+#include <bits/stdc++.h>
+using namespace std;
+string s;
+int main() {
+
+    ios_base::sync_with_stdio(false);
+    cin.tie(NULL);
+    cout.tie(NULL);
+
+    cin >> s;
+    bool ret_flag = true;
+    if (s.length() == 1)
+        ret_flag = false;
+    for (int i=0; i<s.length()-1; i++) {
+        if (s[i] == 'p') {
+            if (s[i+1] == 'i' && i != s.length()-3) i++;
+            else ret_flag = false;
+        } else if (s[i] == 'k') {
+            if (s[i+1] == 'a' && i != s.length()-3) i++;
+            else ret_flag = false;
+        } else if (s[i] == 'c') {
+            if (i != s.length()-2 && s[i+1] == 'h' && s[i+2] == 'u') i += 2;
+            else ret_flag = false;
+        } else
+            ret_flag = false;
+    }
+
+    if (ret_flag) cout << "YES\n";
+    else cout << "NO\n";
+
+    return 0;
+}
\ No newline at end of file
diff --git a/src/week4/BOJ14405/BOJ14405_V2.cpp b/src/week4/BOJ14405/BOJ14405_V2.cpp
new file mode 100644
index 0000000..444c810
--- /dev/null
+++ b/src/week4/BOJ14405/BOJ14405_V2.cpp
@@ -0,0 +1,26 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+int main() {
+
+    ios_base::sync_with_stdio(false);
+    cin.tie(NULL);
+    cout.tie(NULL);
+
+    string s;
+    cin >> s;
+
+    bool ret_flag = true;
+    for (int i = 0; i < s.length(); i++) {
+        if (i < s.length()-1 && (s.substr(i,2) == "pi" || s.substr(i,2) == "ka")) i++;
+        else if (i < s.length()-2 && s.substr(i,3) == "chu") i+=2;
+        else ret_flag = false;
+    }
+
+    if (ret_flag) cout << "YES\n";
+    else cout << "NO\n";
+
+
+
+    return 0;
+}
\ No newline at end of file