foo.cc: In function 'void dFs(int)':
foo.cc:31:2: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
   31 |  if(mark[x])top[x]=x;dfn[x]=++cnt;
      |  ^~
foo.cc:31:22: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'if'
   31 |  if(mark[x])top[x]=x;dfn[x]=++cnt;
      |                      ^~~
foo.cc: In function 'void calc(int, int, int)':
foo.cc:41:2: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
   41 |  if(!v[w[x]])bt[w[x]]=1,sum++;v[w[x]]++;
      |  ^~
foo.cc:41:31: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'if'
   41 |  if(!v[w[x]])bt[w[x]]=1,sum++;v[w[x]]++;
      |                               ^
foo.cc: In function 'int main()':
foo.cc:53:7: error: incomplete type 'std::ios' {aka 'std::basic_ios<char>'} used in nested name specifier
   53 |  ios::sync_with_stdio(false);
      |       ^~~~~~~~~~~~~~~
foo.cc:54:2: error: 'cin' was not declared in this scope
   54 |  cin.tie(0);
      |  ^~~
foo.cc:6:1: note: 'std::cin' is defined in header '<iostream>'; did you forget to '#include <iostream>'?
    5 | #include<cmath>
  +++ |+#include <iostream>
    6 | using namespace std;
foo.cc:55:2: error: 'cout' was not declared in this scope
   55 |  cout.tie(0);
      |  ^~~~
foo.cc:55:2: note: 'std::cout' is defined in header '<iostream>'; did you forget to '#include <iostream>'?
foo.cc:56:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   56 |  scanf("%d%d",&n,&m);
      |  ~~~~~^~~~~~~~~~~~~~
foo.cc:58:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   58 |   scanf("%d",&w[i]),b[i]=w[i];
      |   ~~~~~^~~~~~~~~~~~
foo.cc:65:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   65 |   scanf("%d%d",&x,&y);
      |   ~~~~~^~~~~~~~~~~~~~
foo.cc:74:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   74 |   scanf("%d%d",&x,&y);
      |   ~~~~~^~~~~~~~~~~~~~

Found 4 testcases.
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