diff --git "a/problems/baekjoon/2303_\354\210\253\354\236\220 \352\262\214\354\236\204/jaeseok.py" "b/problems/baekjoon/2303_\354\210\253\354\236\220 \352\262\214\354\236\204/jaeseok.py"
index e69de29..4e55cca 100644
--- "a/problems/baekjoon/2303_\354\210\253\354\236\220 \352\262\214\354\236\204/jaeseok.py"	
+++ "b/problems/baekjoon/2303_\354\210\253\354\236\220 \352\262\214\354\236\204/jaeseok.py"	
@@ -0,0 +1,18 @@
+n = int(input())
+score = []
+
+for _ in range(n):
+  card = list(map(int, input().split()))
+  max_score = 0
+  for one in range(5):
+    for two in range(one+1, 5):
+      for three in range(two+1, 5):
+        first = (card[one] + card[two] + card[three]) % 10
+        if max_score < first:
+          max_score = first
+  score.append(max_score)
+
+for i in range(n-1, -1, -1):
+  if score[i] == max(score):
+    print(i+1)
+    break
\ No newline at end of file
diff --git "a/problems/baekjoon/2869_\353\213\254\355\214\275\354\235\264\353\212\224 \354\230\254\353\235\274\352\260\200\352\263\240 \354\213\266\353\213\244/jaeseok.py" "b/problems/baekjoon/2869_\353\213\254\355\214\275\354\235\264\353\212\224 \354\230\254\353\235\274\352\260\200\352\263\240 \354\213\266\353\213\244/jaeseok.py"
index e69de29..663dc82 100644
--- "a/problems/baekjoon/2869_\353\213\254\355\214\275\354\235\264\353\212\224 \354\230\254\353\235\274\352\260\200\352\263\240 \354\213\266\353\213\244/jaeseok.py"	
+++ "b/problems/baekjoon/2869_\353\213\254\355\214\275\354\235\264\353\212\224 \354\230\254\353\235\274\352\260\200\352\263\240 \354\213\266\353\213\244/jaeseok.py"	
@@ -0,0 +1,8 @@
+a, b, v = map(int, input().split())
+
+# 도달하는 날 x일, 총 올라는 횟수 x번, 내려오는 횟수 (x-1)번
+# ax - b(x-1) = v
+# x = (v - b) / (a - b)
+k = (v - b) / (a - b)
+res = int(k) if k == int(k) else int(k) + 1 # 삼항 연산자 사용
+print(res)
\ No newline at end of file
diff --git "a/problems/programmers/lv0/OX\355\200\264\354\246\210/jaeseok.py" "b/problems/programmers/lv0/OX\355\200\264\354\246\210/jaeseok.py"
index e69de29..30dd36d 100644
--- "a/problems/programmers/lv0/OX\355\200\264\354\246\210/jaeseok.py"
+++ "b/problems/programmers/lv0/OX\355\200\264\354\246\210/jaeseok.py"
@@ -0,0 +1,21 @@
+# solution 1
+def solution(quiz):
+  answer = []
+  for i in range(quiz):
+    res = quiz[i].split()
+    if res[1] == '+':
+      if int(res[0]) + int(res[2]) == int(res[4]):
+        answer.append('O')
+      else:
+        answer.append('X')
+    if res[1] == '-':
+      if int(res[0]) - int(res[2]) == int(res[4]):
+        answer.append('O')
+      else:
+        answer.append('X')
+  return answer
+
+# solution 2
+# eval 함수는 매개변수로 받은 expression(우리가 아는 일반적인 사칙연산 '식')을 문자열로 받아서, 실행하는 함수다. 
+def solution(quiz):
+  return ['O' if eval(i.replace('=', '==')) else 'X' for i in quiz]
\ No newline at end of file