diff --git a/2.add-two-numbers.ts b/2.add-two-numbers.ts
new file mode 100644
index 0000000..82add46
--- /dev/null
+++ b/2.add-two-numbers.ts
@@ -0,0 +1,17 @@
+// @leet start
+/**
+ * Definition for singly-linked list.
+ * class ListNode {
+ *     val: number
+ *     next: ListNode | null
+ *     constructor(val?: number, next?: ListNode | null) {
+ *         this.val = (val===undefined ? 0 : val)
+ *         this.next = (next===undefined ? null : next)
+ *     }
+ * }
+ */
+
+function addTwoNumbers(l1: ListNode | null, l2: ListNode | null): ListNode | null {
+    
+};
+// @leet end
\ No newline at end of file
diff --git a/4.median-of-two-sorted-arrays.ts b/4.median-of-two-sorted-arrays.ts
new file mode 100644
index 0000000..2d60e45
--- /dev/null
+++ b/4.median-of-two-sorted-arrays.ts
@@ -0,0 +1,44 @@
+// @leet start
+function findMedianSortedArrays(nums1: number[], nums2: number[]): number {
+	const merged: number[] = [];
+
+	let aIndex = 0;
+	let bIndex = 0;
+	while (true) {
+		const a = nums1[aIndex];
+		const b = nums2[bIndex];
+
+		if (a === undefined && b === undefined) {
+			break;
+		}
+		if (a === undefined && b !== undefined) {
+			merged.push(b);
+			bIndex++;
+		}
+		if (a !== undefined && b === undefined) {
+			merged.push(a);
+			aIndex++;
+		}
+		if (a !== undefined && b !== undefined) {
+			if (a <= b) {
+				merged.push(a);
+				aIndex++;
+			} else {
+				merged.push(b);
+				bIndex++;
+			}
+		}
+	}
+
+	let median: number;
+	if (merged.length % 2 === 0) {
+		const left = Math.floor((merged.length - 1) / 2);
+		const right = left + 1;
+		median = (merged[left] + merged[right]) / 2;
+	} else {
+		median = merged[(merged.length - 1) / 2];
+	}
+
+	return median;
+}
+// @leet end