diff --git a/src/ls.cpp b/src/ls.cpp
index ceed5c5..07343b7 100644
--- a/src/ls.cpp
+++ b/src/ls.cpp
@@ -38,7 +38,16 @@ LUT* LUTCircuit::ls_pick() {
 
     if(unsat.size() == 0) return nullptr;
 
-    return unsat[rand() % unsat.size()];
+    pick = unsat[rand() % unsat.size()];
+
+    if(pick->fanins.size() == 0) {
+        return pick;
+    }
+
+    if(rand() % 10000 < 5000) {
+        return pick->fanins[rand() % pick->fanins.size()];
+    }
+    return pick;
 }
 
 void LUTCircuit::ls_flip(LUT *lut) {
@@ -68,11 +77,41 @@ void LUTCircuit::ls_flip(LUT *lut) {
 
 void LUTCircuit::ls_update(std::vector<LUT*> &unsat) {
 
-    // printf("?????????????????ls_update\n");
+    if(rand() % 10000 <= OPT(sp) * 10000) {
 
-    // if(rand() % 10000 <= OPT(sp)) {
-
-    // } else {
+        for(LUT* lut : luts) {
+            if(lut->vsat) {
+                if(lut->vunat_cost - OPT(vsat_inc) >= 1) {
+                    lut->vunat_cost -= OPT(vsat_inc);
+                }
+            }
+            if(!lut->vsat) {
+                unsat.push_back(lut);
+            }
+            if(!lut->uptag) {
+                if(lut->up_cost - OPT(up_inc) >= 1) {
+                    lut->up_cost -= OPT(up_inc);
+                }
+            }
+            for(int i=lut->fanins.size(); i<lut->fanins.size()+lut->inner_gates.size(); i++) {
+                Gate* g = lut->inner_gates[i-lut->fanins.size()];
+                LUT::FaultInfo &fi = lut->fault_table[i][lut->input_var];
+                if(fi.fd[0] && g->fault_detected_weight[0] - OPT(fw_inc) >= 1) {
+                    g->fault_detected_weight[0] -= OPT(fw_inc);
+                }
+                if(fi.fd[1] && g->fault_detected_weight[1] - OPT(fw_inc) >= 1) {
+                    g->fault_detected_weight[1] -= OPT(fw_inc);
+                }
+                if(fi.fd[0] && g->fault_propagated_weight[0] - OPT(fw_inc) >= 1) {
+                    g->fault_propagated_weight[0] -= OPT(fw_inc);
+                }
+                if(fi.fd[1] && g->fault_propagated_weight[1] + OPT(fw_inc) >= 1) {
+                    g->fault_propagated_weight[1] -= OPT(fw_inc);
+                }
+            }
+        }
+        
+    } else {
 
         for(LUT* lut : luts) {
             if(!lut->vsat) {
@@ -119,7 +158,7 @@ void LUTCircuit::ls_update(std::vector<LUT*> &unsat) {
                 }
             }
         }
-    // }
+    }
 }
 
 void LUTCircuit::ls_main() {
@@ -360,13 +399,13 @@ void LUTCircuit::ls_gen_sol(const TMP_FAULT &target) {
         best_sol.push_back(lut->value);
     }
     
-    for(int step=0; ; step++) {
+    for(int step=0; step<OPT(max_step_coeff)*luts.size(); step++) {
         // printf("step: %d\n", step);
 
         LUT* pick = ls_pick();
 
         if(pick == nullptr) {
-            break;
+            pick = luts[rand() % luts.size()];
         }
 
         // pick->cal_score();
diff --git a/src/paras.h b/src/paras.h
index 26cccbb..1f1aae8 100644
--- a/src/paras.h
+++ b/src/paras.h
@@ -7,17 +7,18 @@
 
 //        name,       type,  short-name,must-need, default ,low, high, comments
 #define PARAS \
-    PARA( seed         , int    , '\0'  ,  false   , 17    , 0  , 100000000 , "max input numbers of LUT") \
-    PARA( lut          , int    , '\0'  ,  false   , 8     , 0  , 30        , "max input numbers of LUT") \
-    PARA( sp           , double , '\0'  ,  false   , 0.01  , 0  , 1         , "max input numbers of LUT") \
-    PARA( brk_sp       , double , '\0'  ,  false   , 0.05  , 0  , 1         , "max input numbers of LUT") \
-    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( 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( seed              , int    , '\0'  ,  false   , 17    , 0  , 100000000 , "max input numbers of LUT") \
+    PARA( lut               , int    , '\0'  ,  false   , 8     , 0  , 30        , "max input numbers of LUT") \
+    PARA( sp                , double , '\0'  ,  false   , 0.01  , 0  , 1         , "max input numbers of LUT") \
+    PARA( brk_sp            , double , '\0'  ,  false   , 0.05  , 0  , 1         , "max input numbers of LUT") \
+    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( 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")
 //            name,   short-name, must-need, default, comments
 #define STR_PARAS \
     STR_PARA( instance   , 'i'   ,  true    , "" , ".bench format instance")