diff --git a/6.cpp b/6.cpp
index 3922abb..9611f4b 100644
--- a/6.cpp
+++ b/6.cpp
@@ -1,22 +1,23 @@
 // 92
 #include <cstdio>
 using namespace std;
-int c;
+bool ch[20];
 int n;
 void dfs(int now)
 {
-    if (now == n)
+    if (now > n)
     {
         for (int i = 1; i <= n; ++i)
         {
-            if (c & (1 << i))
+            if (ch[i])
                 printf("%d ", i);
         }
         puts("");
         return;
     }
+    ch[now]=0;
     dfs(now + 1);
-    c &= (1 << now);
+    ch[now]=1;
     dfs(now + 1);
 }
 int main()