diff --git a/code_study/Baekjoon/python/15873.py b/code_study/Baekjoon/python/15873.py
new file mode 100644
index 0000000..4a3f72f
--- /dev/null
+++ b/code_study/Baekjoon/python/15873.py
@@ -0,0 +1 @@
+print(eval("+".join(s if len(s := input().rstrip()) == 2 else [s[0:2], s[2:]] if s[1] == "0" else [s[0], s[1:]])))
\ No newline at end of file
diff --git a/code_study/Baekjoon/swift/1516.swift b/code_study/Baekjoon/swift/1516.swift
new file mode 100644
index 0000000..48bbafc
--- /dev/null
+++ b/code_study/Baekjoon/swift/1516.swift
@@ -0,0 +1,93 @@
+import Foundation
+
+final class FileIO {
+    private let buffer:[UInt8]
+    private var index: Int = 0
+
+    init(fileHandle: FileHandle = FileHandle.standardInput) {
+        
+        buffer = Array(try! fileHandle.readToEnd()!) + [UInt8(0)]
+    }
+
+    @inline(__always) private func read() -> UInt8 {
+        defer { index += 1 }
+        return buffer[index]
+    }
+
+    @inline(__always) func readInt() -> Int {
+        var sum = 0
+        var now = read()
+        var isPositive = true
+
+        while now == 10 || now == 32 { now = read() }
+        if now == 45 { isPositive = false; now = read() }
+
+        while now >= 48, now <= 57 {
+            sum = sum * 10 + Int(now-48)
+            now = read()
+        }
+
+        return sum * (isPositive ? 1 : -1)
+    }
+}
+
+func main() {
+    let fp = FileIO()
+    
+    let N = fp.readInt()
+    
+    var next_build: [[Int]] = Array(repeating: [], count: N+1)
+    var build_time: [Int] = Array(repeating: 0, count: N+1)
+    
+    var qu: [Int] = Array(repeating: 0, count: N+1)
+    var front = 0, rear = 0
+    
+    var indegree: [Int] = Array(repeating: 0, count: N+1)
+
+    for n in 1...N {
+        build_time[n] = fp.readInt()
+        
+        while true {
+            let m = fp.readInt()
+            if m == -1 {
+                break
+            }
+            
+            next_build[m].append(n)
+            indegree[n] += 1
+        }
+    }
+    
+    for n in 1...N {
+        if indegree[n] == 0 {
+            qu[rear] = n
+            rear += 1
+        }
+    }
+    
+    var res: [Int] = []
+    for n in build_time {
+        res.append(n)
+    }
+    
+    while front < rear {
+        let now = qu[front]
+        front += 1
+        
+        for nxt in next_build[now] {
+            indegree[nxt] -= 1
+            if indegree[nxt] == 0 {
+                qu[rear] = nxt
+                rear += 1
+            }
+            
+            res[nxt] = max(res[nxt], res[now] + build_time[nxt])
+        }
+    }
+    
+    for n in 1...N {
+        print(res[n])
+    }
+}
+
+main()