answer.code: In function ‘void dfs(int)’:
answer.code:21:12: error: ‘n’ was not declared in this scope
   21 |     if (x==n+1)
      |            ^
answer.code:23:18: error: ‘calc’ was not declared in this scope
   23 |         ans=(ans+calc());
      |                  ^~~~
answer.code: In function ‘void mian()’:
answer.code:31:10: warning: ignoring return value of ‘int scanf(const char*, ...)’ declared with attribute ‘warn_unused_result’ [-Wunused-result]
   31 |     scanf("%d",&n);
      |     ~~~~~^~~~~~~~~
answer.code:34:14: warning: ignoring return value of ‘int scanf(const char*, ...)’ declared with attribute ‘warn_unused_result’ [-Wunused-result]
   34 |         scanf("%s",s+1);
      |         ~~~~~^~~~~~~~~~