diff --git a/69.sqrt-x.java b/69.sqrt-x.java
new file mode 100644
index 0000000..f866584
--- /dev/null
+++ b/69.sqrt-x.java
@@ -0,0 +1,23 @@
+/*
+ * @lc app=leetcode id=69 lang=java
+ *
+ * [69] Sqrt(x)
+ */
+
+// @lc code=start
+class Solution {
+    public int mySqrt(int x) {
+        long l = 0, r = Integer.MAX_VALUE;
+        while(r-l > 1) {
+            long mid = l + (r-l)/2;
+            if(mid * mid <= (long)x) {
+                l = mid;
+            } else {
+                r = mid;
+            }
+        }
+        return (int)l;
+    }
+}
+// @lc code=end
+