diff --git a/src/ls.cpp b/src/ls.cpp
index 07343b7..e4541e2 100644
--- a/src/ls.cpp
+++ b/src/ls.cpp
@@ -44,7 +44,7 @@ LUT* LUTCircuit::ls_pick() {
         return pick;
     }
 
-    if(rand() % 10000 < 5000) {
+    if(rand() % 10000 < 3000) {
         return pick->fanins[rand() % pick->fanins.size()];
     }
     return pick;
diff --git a/src/paras.h b/src/paras.h
index 1f1aae8..e71aa9d 100644
--- a/src/paras.h
+++ b/src/paras.h
@@ -14,11 +14,11 @@
     PARA( t                 , int    , '\0'  ,  false   , 30    , 0  , 1000      , "max input numbers of LUT") \
     PARA( vsat_inc          , int    , '\0'  ,  false   , 1     , 0  , 100000    , "max input numbers of LUT") \
     PARA( vsat_max          , int    , '\0'  ,  false   , 10000 , 0  , 100000    , "max input numbers of LUT") \
-    PARA( fw_inc            , int    , '\0'  ,  false   , 1     , 0  , 1000      , "max input numbers of LUT") \
-    PARA( fw_max            , int    , '\0'  ,  false   , 500   , 0  , 1000      , "max input numbers of LUT") \
+    PARA( fw_inc            , int    , '\0'  ,  false   , 2     , 0  , 1000      , "max input numbers of LUT") \
+    PARA( fw_max            , int    , '\0'  ,  false   , 10000 , 0  , 1000      , "max input numbers of LUT") \
     PARA( up_inc            , int    , '\0'  ,  false   , 1     , 0  , 1000      , "max input numbers of LUT") \
-    PARA( up_max            , int    , '\0'  ,  false   , 1000  , 0  , 1000      , "max input numbers of LUT") \
-    PARA( max_step_coeff    , double , '\0'  ,  false   , 10.0   , 1  , 1000      , "max input numbers of LUT")
+    PARA( up_max            , int    , '\0'  ,  false   , 10000 , 0  , 1000      , "max input numbers of LUT") \
+    PARA( max_step_coeff    , double , '\0'  ,  false   , 10.0  , 1  , 1000      , "max input numbers of LUT")
 //            name,   short-name, must-need, default, comments
 #define STR_PARAS \
     STR_PARA( instance   , 'i'   ,  true    , "" , ".bench format instance")