diff --git a/src/main.rs b/src/main.rs
index c120139..97c888d 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -17,6 +17,7 @@ use params::*;
 use vec::Vector;
 
 use hashbrown::{hash_set::Entry, HashMap, HashSet};
+use rayon::prelude::*;
 use seq_macro::seq;
 use std::time::Instant;
 
@@ -167,6 +168,23 @@ fn find_binary_expressions_left(
     });
 }
 
+fn find_binary_expressions_left_multithread_dfs(
+    cache: &Cache,
+    hashset_cache: &HashSetCache,
+    n: usize,
+    k: usize,
+    er: &Expr,
+) {
+    seq!(op_len in 1..=5 {
+        if n <= k + op_len {
+            return;
+        };
+        cache[n - k - op_len].par_iter().for_each(|el| {
+            find_binary_operators(&mut CacheLevel::new(), cache, hashset_cache, n, el, er, op_len);
+        });
+    });
+}
+
 fn find_binary_expressions_right(
     cn: &mut CacheLevel,
     cache: &Cache,
@@ -314,8 +332,6 @@ fn find_expressions_multithread(
     mut_hashset_cache: &mut HashSetCache,
     n: usize,
 ) {
-    use rayon::prelude::*;
-
     let cache = &mut_cache;
     let hashset_cache = &mut_hashset_cache;
 
@@ -324,26 +340,24 @@ fn find_expressions_multithread(
         .flat_map(|k| {
             cache[k].par_iter().map(move |r| {
                 let mut cn = CacheLevel::new();
-                find_binary_expressions_left(&mut cn, cache, hashset_cache, n, k, r);
+                if k == 1 && n > MAX_CACHE_LENGTH && n + 1 < MAX_LENGTH && r.var_mask != 0 {
+                    find_binary_expressions_left_multithread_dfs(cache, hashset_cache, n, k, r);
+                } else {
+                    find_binary_expressions_left(&mut cn, cache, hashset_cache, n, k, r);
+                }
                 cn
             })
         })
-        .chain(
-            std::iter::once_with(|| {
-                let mut cn = CacheLevel::new();
-                find_parens_expressions(&mut cn, cache, hashset_cache, n);
-                cn
-            })
-            .par_bridge(),
-        )
-        .chain(
-            std::iter::once_with(|| {
-                let mut cn = CacheLevel::new();
-                find_unary_expressions(&mut cn, cache, hashset_cache, n);
-                cn
-            })
-            .par_bridge(),
-        )
+        .chain(rayon::iter::once(()).map(|()| {
+            let mut cn = CacheLevel::new();
+            find_parens_expressions(&mut cn, cache, hashset_cache, n);
+            cn
+        }))
+        .chain(rayon::iter::once(()).map(|()| {
+            let mut cn = CacheLevel::new();
+            find_unary_expressions(&mut cn, cache, hashset_cache, n);
+            cn
+        }))
         .flatten_iter()
         .collect();