diff --git a/code_study/Baekjoon/python/17404.py b/code_study/Baekjoon/python/17404.py
new file mode 100644
index 0000000..2ae0d30
--- /dev/null
+++ b/code_study/Baekjoon/python/17404.py
@@ -0,0 +1,37 @@
+import sys
+
+input = sys.stdin.readline
+
+maxCost = 1000
+N = int(input())
+R = []
+G = []
+B = []
+
+for _ in range(N) :
+    r, g, b = map(int, input().split())
+    R.append(r)
+    G.append(g)
+    B.append(b)
+
+result = []
+
+for i in range(3) :
+    dpR = [maxCost if i != 0 else R[0]]
+    dpG = [maxCost if i != 1 else G[0]]
+    dpB = [maxCost if i != 2 else B[0]]
+    
+    for n in range(1, N) :
+        r, g, b = R[n], G[n], B[n]
+        dpR.append(r + min(dpG[n-1], dpB[n-1]))
+        dpG.append(g + min(dpR[n-1], dpB[n-1]))
+        dpB.append(b + min(dpR[n-1], dpG[n-1]))
+    
+    if i==0 :
+        result.append(min(dpG[N-1], dpB[N-1]))
+    elif i==1 :
+        result.append(min(dpR[N-1], dpB[N-1]))
+    else :
+        result.append(min(dpR[N-1], dpG[N-1]))
+
+print(min(result))
\ No newline at end of file
diff --git a/code_study/Baekjoon/swift/1918.swift b/code_study/Baekjoon/swift/1918.swift
new file mode 100644
index 0000000..88356e5
--- /dev/null
+++ b/code_study/Baekjoon/swift/1918.swift
@@ -0,0 +1,51 @@
+func opPriority(_ op: Character) -> Int {
+    return (op == "*") || (op == "/") ? 2 : (op == "+") || (op == "-") ? 1 : 0
+}
+
+func compareToPriority(_ op1: Character, _ op2: Character) -> Bool {
+    return opPriority(op1) >= opPriority(op2)
+}
+
+if let input = readLine() {
+    var result: String = ""
+    var op: [Character] = []
+    
+    for c in input {
+        if "A" <= c && c <= "Z" {
+            result.append(c)
+        }
+        else {
+            if c == "(" {
+                op.append(c)
+            }
+            else if c == ")" {
+                while !op.isEmpty && op.last != "(" {
+                    if let top = op.popLast() {
+                        result.append(top)
+                    }
+                }
+                
+                if !op.isEmpty {
+                    _ = op.popLast()
+                }
+            }
+            else {
+                while !op.isEmpty && compareToPriority(op.last!, c) {
+                    if let top = op.popLast() {
+                        result.append(top)
+                    }
+                }
+                
+                op.append(c)
+            }
+        }
+    }
+    
+    while !op.isEmpty {
+        if let top = op.popLast() {
+            result.append(top)
+        }
+    }
+    
+    print(result)
+}