/in/foo.cc: In function 'int rd()':
/in/foo.cc:9:2: warning: this 'while' clause does not guard... [-Wmisleading-indentation]
  while((c<'0'||c>'9')&&c!='-')c=getchar();if(c=='-')ntv=true;else x=(c^48);c=getchar();
  ^~~~~
/in/foo.cc:9:43: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the 'while'
  while((c<'0'||c>'9')&&c!='-')c=getchar();if(c=='-')ntv=true;else x=(c^48);c=getchar();
                                           ^~
/in/foo.cc: In function 'int main()':
/in/foo.cc:18:29: warning: 'k' may be used uninitialized in this function [-Wmaybe-uninitialized]
  bool l=!(k%2);int f,s,c=cnt-k+1;
                          ~~~^~