diff --git a/HamSungJun/Solution_1323.ts b/HamSungJun/Solution_1323.ts
new file mode 100644
index 0000000..e2f5c72
--- /dev/null
+++ b/HamSungJun/Solution_1323.ts
@@ -0,0 +1,5 @@
+function maximum69Number (num: number): number {
+  let strNum = '' + num
+  strNum = strNum.replace(/6/, '9')
+  return parseInt(strNum)
+};
diff --git a/HamSungJun/Solution_1863.ts b/HamSungJun/Solution_1863.ts
new file mode 100644
index 0000000..5bf64eb
--- /dev/null
+++ b/HamSungJun/Solution_1863.ts
@@ -0,0 +1,45 @@
+function subsetXORSum (nums: number[]): number {
+  if (nums.length === 0) return 0
+  const subSets = [0]
+  for (let i = 0; i <= nums.length; i++) {
+    const visited = new Array(nums.length).fill(false)
+    backTrack({ endLength: i, basket: [], visited, nums, subSets })
+  }
+  return subSets[0]
+}
+
+function backTrack ({ endLength, basket, visited, nums, subSets }: {endLength: number, basket: Array<number>, visited: Array<boolean>, nums: Array<number>, subSets: Array<number>}) : void {
+  if (basket.length === endLength) {
+    console.log(basket)
+    if (basket.length === 0) {
+      subSets[0] += 0
+    } else if (basket.length === 1) {
+      subSets[0] += nums[basket[0]]
+    } else {
+      subSets[0] += calcXOR(basket, nums)
+    }
+  }
+  for (let i = 0; i < nums.length; i++) {
+    if (!visited[i]) {
+      if (basket.length >= 1 && basket[basket.length - 1] > i) {
+        continue
+      }
+      visited[i] = true
+      basket.push(i)
+      backTrack({ endLength, basket, visited, nums, subSets })
+      basket.pop()
+      visited[i] = false
+    }
+  }
+}
+
+function calcXOR (basket: Array<number>, nums: Array<number>) {
+//   console.log('calc', basket, nums)
+  let xorAcc = nums[basket[0]]
+  for (let i = 1; i < basket.length; i++) {
+    xorAcc ^= nums[basket[i]]
+  }
+  return xorAcc
+}
+
+console.log(subsetXORSum([1, 3]))
diff --git a/HamSungJun/Solution_1920.ts b/HamSungJun/Solution_1920.ts
new file mode 100644
index 0000000..5fe7f0b
--- /dev/null
+++ b/HamSungJun/Solution_1920.ts
@@ -0,0 +1,3 @@
+function buildArray (nums: number[]): number[] {
+  return nums.map((num, i) => nums[nums[i]])
+};