diff --git "a/week7/implementation/\353\213\250\354\226\264\353\222\244\354\247\221\352\270\2602/arenran02/Main.c" "b/week7/implementation/\353\213\250\354\226\264\353\222\244\354\247\221\352\270\2602/arenran02/Main.c"
new file mode 100644
index 00000000..8249aea3
--- /dev/null
+++ "b/week7/implementation/\353\213\250\354\226\264\353\222\244\354\247\221\352\270\2602/arenran02/Main.c"
@@ -0,0 +1,93 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <ctype.h>
+
+// 노드 정의
+typedef struct node {
+    char data;
+    struct node* next;
+} node;
+
+// 스택 구조체
+typedef struct {
+    node* top;
+    int size;
+} STACK;
+
+// 스택 함수 정의
+void init_STACK(STACK* s) {
+    s->top = NULL;
+    s->size = 0;
+}
+
+int is_stack_empty(STACK* s) {
+    return s->size == 0;
+}
+
+void push_stack(STACK* s, char data) {
+    node* newnode = malloc(sizeof(node));
+    newnode->data = data;
+    newnode->next = s->top;
+    s->top = newnode;
+    s->size++;
+}
+
+char pop_stack(STACK* s) {
+    if (is_stack_empty(s)) return '\0';
+    node* temp = s->top;
+    char data = temp->data;
+    s->top = temp->next;
+    s->size--;
+    free(temp);
+    return data;
+}
+
+void flush_stack(STACK* s) {
+    while (!is_stack_empty(s)) {
+        printf("%c", pop_stack(s));
+    }
+}
+
+int main() {
+    char str[100001];
+    fgets(str, sizeof(str), stdin);
+
+    STACK s;
+    init_STACK(&s);
+
+    int in_tag = 0;
+
+    for (int i = 0; str[i] != '\0'; i++) {
+        char c = str[i];
+
+        if (c == '<') {
+            // 단어 뒤집기 마무리하고 태그 출력 시작
+            flush_stack(&s);
+            in_tag = 1;
+            printf("%c", c);
+        }
+        else if (c == '>') {
+            in_tag = 0;
+            printf("%c", c);
+        }
+        else if (in_tag) {
+            // 태그 안: 그대로 출력
+            printf("%c", c);
+        }
+        else {
+            // 태그 밖
+            if (c == ' ' || c == '\n') {
+                flush_stack(&s);
+                printf("%c", c);
+            } else {
+                push_stack(&s, c);
+            }
+        }
+    }
+
+    // 마지막 남은 단어 뒤집기
+    flush_stack(&s);
+
+    return 0;
+}
diff --git "a/week7/implementation/\355\214\214\354\235\274\354\240\225\353\246\254/arenran02/Main.cpp" "b/week7/implementation/\355\214\214\354\235\274\354\240\225\353\246\254/arenran02/Main.cpp"
new file mode 100644
index 00000000..bfb6ce86
--- /dev/null
+++ "b/week7/implementation/\355\214\214\354\235\274\354\240\225\353\246\254/arenran02/Main.cpp"
@@ -0,0 +1,26 @@
+#include <iostream>
+#include <map>
+#include <string>
+
+int main() {
+    int N;
+    std::cin >> N;
+    std::map<std::string, int> extensionCount;
+
+    for (int i = 0; i < N; ++i) {
+        std::string filename;
+        std::cin >> filename;
+
+        size_t pos = filename.rfind('.');
+        if (pos != std::string::npos) {
+            std::string extension = filename.substr(pos + 1);
+            ++extensionCount[extension];
+        }
+    }
+
+    for (const auto& pair : extensionCount) {
+        std::cout << pair.first << " " << pair.second << "\n";
+    }
+
+    return 0;
+}
diff --git a/week7/simulation/ZOAC3/arenran02/Main.cpp b/week7/simulation/ZOAC3/arenran02/Main.cpp
new file mode 100644
index 00000000..15ff286e
--- /dev/null
+++ b/week7/simulation/ZOAC3/arenran02/Main.cpp
@@ -0,0 +1,75 @@
+#include <iostream>
+using namespace std;
+ 
+int map[3][10];
+ 
+string top = "qwertyuiop";
+string middle = "asdfghjkl";
+string bottom = "zxcvbnm";
+ 
+struct Info{
+    int r;
+    int c;
+    char hand;
+};
+ 
+Info l, r;
+ 
+Info find_coor(char key){
+    int _r = 0, _c = 0;
+    char hand;
+    for(int i=0; i<top.length(); i++){
+        if(top[i] == key){
+            _r = 0, _c = i;
+            if(i<=4) hand = 'l';
+            else hand = 'r';
+        }
+    }
+    for(int i=0; i<middle.length(); i++){
+        if(middle[i] == key){
+            _r = 1, _c = i;
+            if(i <= 4) hand = 'l';
+            else hand = 'r';
+        }
+    }
+    for(int i=0; i<bottom.length(); i++){
+        if(bottom[i] == key){
+            _r = 2, _c = i;
+            if(i <= 3) hand = 'l';
+            else hand = 'r';
+        }
+    }
+    return {_r, _c, hand};
+}
+ 
+int find_dist(char key){
+    Info key_coor = find_coor(key);
+    int dist = 0;
+    if(key_coor.hand == 'l'){
+        dist = abs(l.r - key_coor.r) + abs(l.c - key_coor.c);
+        l.r = key_coor.r;
+        l.c = key_coor.c;
+    }
+    if(key_coor.hand == 'r'){
+        dist = abs(r.r - key_coor.r) + abs(r.c - key_coor.c);
+        r.r = key_coor.r;
+        r.c = key_coor.c;
+    }
+    return dist;
+}
+ 
+int main(){
+    ios_base::sync_with_stdio(false);
+    cin.tie(0);
+    
+    char left, right; cin>>left>>right;
+    string s; cin>>s;
+    
+    l = find_coor(left);
+    r = find_coor(right);
+    int ans = 0;
+    for(char key: s) ans += find_dist(key);
+    
+    cout<<ans+s.length();
+ 
+}
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