diff --git a/2311. Longest Binary Subsequence Less Than or Equal to K b/2311. Longest Binary Subsequence Less Than or Equal to K
new file mode 100644
index 0000000..d799db7
--- /dev/null
+++ b/2311. Longest Binary Subsequence Less Than or Equal to K	
@@ -0,0 +1,17 @@
+class Solution {
+public:
+    int longestSubsequence(string s, int k) {
+        int res = 0;
+        long long cur = 0;
+        for(int i = s.size() - 1; i >= 0; --i) {
+            char c = s[i];
+            if(c == '0') {
+                res++;
+            } else if(res < 31 && cur + (1LL << res) <= k) {
+                cur += 1LL << res;
+                res++;
+            }
+        }
+        return res;
+    }
+};