Main.cc: In function ‘void divide(long long int, long long int)’:
Main.cc:25:28: error: ‘sqrt’ was not declared in this scope
   25 |  for(long long i = 2; i <= sqrt(nn); i++)
      |                            ^~~~
Main.cc: In function ‘int main()’:
Main.cc:43:9: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result]
   43 |  freopen("data.txt", "r", stdin);
      |  ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~