diff --git a/code_study/Baekjoon/python/3029.py b/code_study/Baekjoon/python/3029.py
new file mode 100644
index 0000000..e067dcf
--- /dev/null
+++ b/code_study/Baekjoon/python/3029.py
@@ -0,0 +1,17 @@
+h1, m1, s1 = map(int, input().split(":"))
+h2, m2, s2 = map(int, input().split(":"))
+
+if h1 == h2 and m1 == m2 and s1 == s2 :
+    print("24:00:00")
+else :
+    t1 = h1*3600 + m1*60 + s1
+    t2 = h2*3600 + m2*60 + s2
+
+    diff = t2 - t1 if t2 > t1 else t2 - t1 + 24 * 3600
+    
+    h = diff // 3600
+    m = (diff % 3600) // 60
+    s = diff % 60
+    
+    print(f"{h:02d}:{m:02d}:{s:02d}")
+    
\ No newline at end of file
diff --git a/code_study/Baekjoon/swift/17387.swift b/code_study/Baekjoon/swift/17387.swift
new file mode 100644
index 0000000..51cf6d8
--- /dev/null
+++ b/code_study/Baekjoon/swift/17387.swift
@@ -0,0 +1,70 @@
+func crossProduct(_ X: [Int], _ Y: [Int], _ Z: [Int]) -> Int {
+    let XY = [Y[0] - X[0], Y[1] - X[1]]
+    let XZ = [Z[0] - X[0], Z[1] - X[1]]
+    
+    let val = XY[0]*XZ[1] - XY[1]*XZ[0]
+    
+    return val > 0 ? 1 : val < 0 ? -1 : 0
+}
+
+func pointSort(_ x1: Int, _ y1: Int, _ x2: Int, _ y2: Int)-> ([Int], [Int]) {
+    if x1 < x2 {
+        return ([x1, y1], [x2,y2])
+    }
+    else if x1 > x2 {
+        return ([x2, y2], [x1,y1])
+    }
+    else if y1 < y2 {
+        return ([x1, y1], [x2,y2])
+    }
+    else {
+        return ([x2, y2], [x1,y1])
+    }
+}
+
+func pointCompare(_ X: [Int], _ Y: [Int]) -> Bool {
+    if X[0] < Y[0] {
+        return true
+    }
+    else if X[0] == Y[0] && X[1] <= Y[1] {
+        return true
+    }
+    else {
+        return false
+    }
+}
+
+func main() -> Int {
+    guard let line1 = readLine(),
+          let line2 = readLine()
+    else { return -1 }
+    
+    let L1 = line1.split(separator: " ").compactMap{Int($0)}
+    let L2 = line2.split(separator: " ").compactMap{Int($0)}
+    
+    let x1 = L1[0], y1 = L1[1], x2 = L1[2], y2 = L1[3]
+    let x3 = L2[0], y3 = L2[1], x4 = L2[2], y4 = L2[3]
+    
+    let (A, B) = pointSort(x1, y1, x2, y2)
+    let (C, D) = pointSort(x3, y3, x4, y4)
+
+    let ABCD = crossProduct(A, B, C) * crossProduct(A, B, D)
+    let CDAB = crossProduct(C, D, A) * crossProduct(C, D, B)
+
+    if ABCD == 0 && CDAB == 0 {
+        if pointCompare(A, D) && pointCompare(C, B) {
+            return 1
+        }
+        else {
+            return 0
+        }
+    }
+    
+    if ABCD <= 0 && CDAB <= 0 {
+        return 1
+    }
+    
+    return 0
+}
+
+print(main())
\ No newline at end of file