View Compilation Error

0_0_38738916_9001.cpp: In function 'void dfs(long long int, long long int)':
0_0_38738916_9001.cpp:46:26: error: 'si' was not declared in this scope; did you mean 'sz'?
   46 |         dep[u] += __lg(2*si-1)+1;
      |                          ^~
      |                          sz