diff --git a/best-time-to-buy-and-sell-stock/Lustellz.ts b/best-time-to-buy-and-sell-stock/Lustellz.ts
new file mode 100644
index 000000000..b5e0dcf3d
--- /dev/null
+++ b/best-time-to-buy-and-sell-stock/Lustellz.ts
@@ -0,0 +1,21 @@
+function maxProfit(prices: number[]): number {
+
+        // Runtime: 1ms
+        // Memory: 66.23MB
+        let minPrice: number = prices[0];
+        let maxProfit: number = 0;
+
+        for (let i = 1; i < prices.length; i++) {
+    // 1. compare the number later than now
+            if (prices[i] < minPrice) {
+    // 2. if there's bigger number later, set it as the standard
+                minPrice = prices[i];
+            } else {
+                maxProfit = Math.max(maxProfit, prices[i] - minPrice);
+            }
+        }
+        return maxProfit;
+
+        // What I was planning to do: Recursion
+        // Result: referring other's code
+};