diff --git a/fe_util.py b/fe_util.py
index f498df9..8c5ce7b 100644
--- a/fe_util.py
+++ b/fe_util.py
@@ -99,10 +99,10 @@ def crosscount(df, col_list):
 
 
 def aggregate(df, num_col, col, stat_list = AGGREGATE_TYPE):
-    agg_dict = {}
+    agg_list = []
     for i in stat_list:
-        agg_dict['AGG_{}_{}_{}'.format(i, num_col, col)] = i
-    agg_result = df.groupby([col])[num_col].agg(agg_dict)
+        agg_list.append(('AGG_{}_{}_{}'.format(i, num_col, col), i))
+    agg_result = df.groupby([col])[num_col].agg(agg_list)
     r = left_merge(df, agg_result, on = [col])
     df = concat([df, r])
     return df
@@ -112,9 +112,9 @@ def nunique(df, id_col, col):
     """
     get id group_by(id) nunique
     """
-    agg_dict = {}
-    agg_dict['NUNIQUE_{}_{}'.format(id_col, col)] = 'nunique'
-    agg_result = df.groupby([col])[id_col].agg(agg_dict)
+    agg_list = []
+    agg_list.append(('NUNIQUE_{}_{}'.format(id_col, col), 'nunique'))
+    agg_result = df.groupby([col])[id_col].agg(agg_list)
     r = left_merge(df, agg_result, on = [col])
     df = concat([df, r])
     return df
@@ -124,11 +124,11 @@ def histstat(df, id_col, col, stat_list = AGGREGATE_TYPE):
     """
     get id group_by(id) histgram statitics
     """
-    agg_dict = {}
+    agg_list = []
     for i in stat_list:
-        agg_dict['HISTSTAT_{}_{}_{}'.format(i, id_col, col)] = i
+        agg_list.append(('HISTSTAT_{}_{}_{}'.format(i, id_col, col), i))
     df['temp_count'] = df.groupby(id_col)[id_col].transform('count')
-    agg_result = df.groupby([col])['temp_count'].agg(agg_dict)
+    agg_result = df.groupby([col])['temp_count'].agg(agg_list)
     r = left_merge(df, agg_result, on = [col])
     df = concat([df, r])
     del df['temp_count']
diff --git a/main.py b/main.py
index ff11691..b13c549 100644
--- a/main.py
+++ b/main.py
@@ -29,6 +29,7 @@
     file_name = 'train.tiny.csv'
     target_name = 'Label'
     id_index = 'Id'
+    min_data = 200  # must be a factor of number of instances
 
     # get parameters from tuner
     RECEIVED_PARAMS = nni.get_next_parameter()
@@ -43,7 +44,8 @@
     
     # raw feaure + sample_feature
     df = name2feature(df, sample_col, target_name)
-    feature_imp, val_score = lgb_model_train(df,  _epoch = 1000, target_name = target_name, id_index = id_index)
+    feature_imp, val_score = lgb_model_train(df, _epoch=1000, target_name=target_name,
+                                             id_index=id_index, min_data=min_data)
     nni.report_final_result({
         "default":val_score, 
         "feature_importance":feature_imp
diff --git a/model.py b/model.py
index c827848..d26ffc0 100644
--- a/model.py
+++ b/model.py
@@ -51,7 +51,7 @@ def train_test_split(X, y, test_size, random_state=2018):
     return [X_train, X_test, y_train, y_test]
 
 
-def lgb_model_train( df, _epoch=1000, target_name='Label', id_index='Id'):
+def lgb_model_train( df, _epoch=1000, target_name='Label', id_index='Id', min_data=200):
     df = df.loc[df[target_name].isnull()==False]
     feature_name = [i for i in df.columns if i not in [target_name, id_index]]
     for i in feature_name:
@@ -68,7 +68,7 @@ def lgb_model_train( df, _epoch=1000, target_name='Label', id_index='Id'):
             'num_threads': 4,
             'num_leaves':64, 
             'learning_rate': 0.05,
-            'min_data': 200, 
+            'min_data': min_data,
             'bagging_fraction': 0.5,
             'feature_fraction': 0.5,
             'max_depth': -1 ,
diff --git a/requirments.txt b/requirements.txt
similarity index 62%
rename from requirments.txt
rename to requirements.txt
index e02fd2e..1adca56 100644
--- a/requirments.txt
+++ b/requirements.txt
@@ -2,5 +2,5 @@ lightgbm
 pandas
 numpy
 sklearn
-nni==0.9.1
-gensim
+nni
+gensim
\ No newline at end of file