diff --git a/백준/30805.py b/백준/30805.py
new file mode 100644
index 0000000..1fdc459
--- /dev/null
+++ b/백준/30805.py
@@ -0,0 +1,41 @@
+import sys
+
+input = sys.stdin.readline
+
+n = int(input())
+A = list(map(int, input().split()))
+m = int(input())
+B = list(map(int, input().split()))
+
+nextA = [[-1] * 101 for _ in range(n+1)]
+nextB = [[-1] * 101 for _ in range(m+1)]
+
+for i in range(n-1, -1 ,-1):
+    for num in range(1, 101):
+        nextA[i][num] = nextA[i+1][num]
+    nextA[i][A[i]] = i
+
+for i in range(m-1, -1 ,-1):
+    for num in range(1, 101):
+        nextB[i][num] = nextB[i+1][num]
+    nextB[i][B[i]] = i
+
+result = []
+i = j = 0
+while i<n and j<m:
+    found = False
+    for num in range(100, 0, -1):
+        posA = nextA[i][num]
+        posB = nextB[j][num]
+        if posA != -1 and posB != -1:
+            result.append(num)
+            i = posA+1
+            j = posB+1
+            found = True
+            break
+    if not found:
+        break
+
+print(len(result))
+if result:
+    print(" ".join(map(str, result)))
\ No newline at end of file
diff --git a/백준/42860.py b/백준/42860.py
new file mode 100644
index 0000000..eba3831
--- /dev/null
+++ b/백준/42860.py
@@ -0,0 +1,38 @@
+def solution(name):
+    Alphabet = {'A' : 1, 'B':2, 'C':3, 'D':4, 'E':5, 'F':6, 'G':7, 'H':8, 'I':9, 'J':10, 'K':11, 'L':12, 'M':13, 'N':14,'O':15,'P':16,'Q':17,'R':18,'S':19,'T':20,'U':21,'V':22,'W':23,'X':24,'Y':25,'Z':26}
+    answer = 0
+    pointer = 1
+    leftpointer = 1
+    rightpointer = 1
+    count=0
+    name_length = len(name)
+    for spell in name:
+        leftpointer = 1
+        rightpointer = 1
+        left_answer = 0
+        right_answer = 0
+        spell_num = Alphabet[spell]
+
+        while(spell_num!=leftpointer):
+            leftpointer -= 1
+            if(leftpointer == 0):
+                leftpointer = 26
+            left_answer += 1
+        while(spell_num!=rightpointer):
+            rightpointer+=1
+            if(rightpointer==27):
+                rightpointer = 1
+            right_answer += 1
+        answer += min(left_answer, right_answer)
+        
+        j = spell_num + 1
+        while j < spell_num and spell_num == 1:
+            j+=1
+        
+        move_case = min(spell_num, name_length - j)
+        answer = min(move_case, answer)
+        rightanswer=answer
+        
+    if name:
+        answer -= 1
+    return answer
\ No newline at end of file
diff --git a/백준/84512.py b/백준/84512.py
new file mode 100644
index 0000000..02fa967
--- /dev/null
+++ b/백준/84512.py
@@ -0,0 +1,31 @@
+import sys
+from collections import deque
+
+sys.setrecursionlimit(10**6)
+
+
+arr_word = ['A', "E", "I", "O", "U"]
+
+alphabet_dict={}
+
+temp = 0
+
+
+
+for i in arr_word:
+    temp += 1
+    alphabet_dict[i] = temp
+    for j in arr_word:
+        temp += 1
+        alphabet_dict[i+j] = temp    
+        for k in arr_word:
+            temp += 1
+            alphabet_dict[i+j+k] = temp
+            for l in arr_word:
+                temp += 1
+                alphabet_dict[i+j+k+l] = temp
+                for m in arr_word:
+                    temp += 1
+                    alphabet_dict[i+j+k+l+m] = temp
+
+
diff --git a/백준/app 2.py b/백준/app 2.py
new file mode 100644
index 0000000..a25e50e
--- /dev/null
+++ b/백준/app 2.py	
@@ -0,0 +1,62 @@
+#!/usr/bin/python3
+from flask import Flask, request, render_template, g
+import sqlite3
+import os
+import binascii
+
+app = Flask(__name__)
+app.secret_key = os.urandom(32)
+
+try:
+    FLAG = open('./flag.txt', 'r').read()
+except:
+    FLAG = '[**FLAG**]'
+
+DATABASE = "database.db"
+if os.path.exists(DATABASE) == False:
+    db = sqlite3.connect(DATABASE)
+    db.execute('create table users(userid char(100), userpassword char(100), userlevel integer);')
+    db.execute(f'insert into users(userid, userpassword, userlevel) values ("guest", "guest", 0), ("admin", "{binascii.hexlify(os.urandom(16)).decode("utf8")}", 0);')
+    db.commit()
+    db.close()
+
+def get_db():
+    db = getattr(g, '_database', None)
+    if db is None:
+        db = g._database = sqlite3.connect(DATABASE)
+    db.row_factory = sqlite3.Row
+    return db
+
+def query_db(query, one=True):
+    cur = get_db().execute(query)
+    rv = cur.fetchall()
+    cur.close()
+    return (rv[0] if rv else None) if one else rv
+
+@app.teardown_appcontext
+def close_connection(exception):
+    db = getattr(g, '_database', None)
+    if db is not None:
+        db.close()
+
+@app.route('/')
+def index():
+    return render_template('index.html')
+
+@app.route('/login', methods=['GET', 'POST'])
+def login():
+    if request.method == 'GET':
+        return render_template('login.html')
+    else:
+        userlevel = request.form.get('userlevel')
+        res = query_db(f"select * from users where userlevel='{userlevel}'")
+        if res:
+            userid = res[0]
+            userlevel = res[2]
+            print(userid, userlevel)
+            if userid == 'admin' and userlevel == 0:
+                return f'hello {userid} flag is {FLAG}'
+            return f'<script>alert("hello {userid}");history.go(-1);</script>'
+        return '<script>alert("wrong");history.go(-1);</script>'
+
+app.run(host='0.0.0.0', port=8000)