diff --git a/code_study/Baekjoon/c/16953.c b/code_study/Baekjoon/c/16953.c
new file mode 100644
index 0000000..650c951
--- /dev/null
+++ b/code_study/Baekjoon/c/16953.c
@@ -0,0 +1,29 @@
+#include <stdio.h>
+
+int main() {
+    int A, B;
+    scanf("%d %d",&A, &B);
+
+    int flag = 0;
+    int count = 1;
+    while(B >= A) {
+        if (A==B) {
+            flag = 1;
+            break;
+        }
+        
+        if (B%2==0) {
+            B /= 2;
+            count++;
+        }
+        else if (B%10==1) {
+            B /= 10;
+            count++;
+        }
+        else break;
+    }
+
+    printf("%d\n", flag ? count : -1);
+
+    return 0;
+}
\ No newline at end of file
diff --git a/code_study/Baekjoon/swift/16953.swift b/code_study/Baekjoon/swift/16953.swift
new file mode 100644
index 0000000..56e56ab
--- /dev/null
+++ b/code_study/Baekjoon/swift/16953.swift
@@ -0,0 +1,27 @@
+if let input = readLine(), let nums = input.split(separator: " ").compactMap({Int($0)}) as? [Int], nums.count == 2 {
+    let A: Int = nums[0]
+    var B: Int = nums[1]
+
+    var count: Int = 1
+    var flag: Bool = false
+    while B >= A {
+        if A == B {
+            flag = true
+            break
+        }
+
+        if B%2 == 0 {
+            B /= 2
+            count+=1
+        }
+        else if B%10 == 1 {
+            B = (B-1)/10
+            count+=1
+        }
+        else {
+            break
+        }
+    }
+
+    print(flag ? count : -1)
+}
\ No newline at end of file