diff --git a/26/02/1680.go b/26/02/1680.go
new file mode 100644
index 0000000..9d398fb
--- /dev/null
+++ b/26/02/1680.go
@@ -0,0 +1,13 @@
+package A
+
+import "math/bits"
+
+func concatenatedBinary(n int) int {
+	var res int64 = 0
+	const mod = 1e9 + 7
+	for i := 0; i < n; i++ {
+		b := bits.Len32(uint32(i + 1))
+		res = ((res << b) + int64(i+1)) % mod
+	}
+	return int(res)
+}