diff --git a/README.md b/README.md
index c0d2f57..967a153 100644
--- a/README.md
+++ b/README.md
@@ -103,9 +103,13 @@ cd ./src/models/swin
 pip install -e . -i https://pypi.tuna.tsinghua.edu.cn/simple/
 ```
 
-> Note: Either GPU or CPU can be installed according to the above steps, and the program will automatically identify the running configuration and environment.  
+> Note: 
 >
-> If you want to use GPU, please install [CUDA-11.3](https://developer.nvidia.com/cuda-11.3.0-download-archive) and [cuDNN-8.2](https://developer.nvidia.com/rdp/cudnn-archive) before.
+> 1.   If `src/straw.cpp:34:10: fatal error: curl/curl.h: No such file or directory` is encountered during installation, enter the following command `sudo apt-get install libcurl-dev libcurl4-openssl-dev libssl-dev` in the terminal or refer: `https://stackoverflow.com/questions/11471690/curl-h-no-such-file-or-directory`.
+>
+> 2.   Either GPU or CPU can be installed according to the above steps, and the program will automatically identify the running configuration and environment.  
+>
+> 3.   If you want to use GPU, please install [CUDA-11.3](https://developer.nvidia.com/cuda-11.3.0-download-archive) and [cuDNN-8.2](https://developer.nvidia.com/rdp/cudnn-archive) before.
 
 ​    
 
diff --git a/src/utils/get_chr_data.py b/src/utils/get_chr_data.py
index 8868018..4c78435 100644
--- a/src/utils/get_chr_data.py
+++ b/src/utils/get_chr_data.py
@@ -164,7 +164,7 @@ def split_list(lst, val):
     return [lst[:lst.index(val)], lst[lst.index(val) + 1:]] if val in lst else [lst]
 
 
-def divide_chr(chr_len_txt, hic_file, assembly_file, modified_assembly_file):
+def divide_chr(chr_len_txt, hic_file, assembly_file, modified_assembly_file, hic_len):
     """
         divide chr
     Args:
@@ -172,6 +172,7 @@ def divide_chr(chr_len_txt, hic_file, assembly_file, modified_assembly_file):
         hic_file: hic file
         assembly_file: assembly file
         modified_assembly_file: modified assembly file
+        hic_len: hic length
 
     Returns:
 
@@ -200,7 +201,10 @@ def divide_chr(chr_len_txt, hic_file, assembly_file, modified_assembly_file):
             assembly_file = modified_assembly_file
 
         # find ctg
-        error_contains_ctg = asy_operate.find_site_ctg_s(assembly_file, chr_len, chr_len + 2)
+        if chr_len + 2 >= hic_len:
+            error_contains_ctg = asy_operate.find_site_ctg_s(assembly_file, chr_len - 2, chr_len)
+        else:
+            error_contains_ctg = asy_operate.find_site_ctg_s(assembly_file, chr_len, chr_len + 2)
 
         # json format
         contain_ctg = json.loads(error_contains_ctg)
@@ -322,7 +326,7 @@ def split_chr(img_file, asy_file, hic_file, cfg_file, device='cpu'):
 
     # split chr
     modified_assembly_file = os.path.join(os.path.dirname(img_file), "chr.assembly")
-    divide_chr(chr_output, hic_file, asy_file, modified_assembly_file)
+    divide_chr(chr_output, hic_file, asy_file, modified_assembly_file, hic_len)
 
     # get chr number
     with open(chr_output, 'r') as file: