/in/foo.cc:8:8: error: expected primary-expression before ']' token
  }e[M<<];
        ^
/in/foo.cc: In function 'void add(int, int)':
/in/foo.cc:14:6: error: 'e' was not declared in this scope
      e[++num].next=head[from];
      ^
/in/foo.cc: In function 'void tarjan(int)':
/in/foo.cc:23:28: error: 'e' was not declared in this scope
      for(int i=head[x];i;i=e[i].next)
                            ^
/in/foo.cc:36:10: error: expected primary-expression before ']' token
          ]!=x)
          ^
/in/foo.cc: In function 'bool two_sat()':
/in/foo.cc:46:7: error: 'i' was not declared in this scope
      ;i<=*n;i++)
       ^
/in/foo.cc:46:11: error: invalid type argument of unary '*' (have 'int')
      ;i<=*n;i++)
           ^
/in/foo.cc: In function 'int main()':
/in/foo.cc:59:7: error: 'i' was not declared in this scope
      ;i<=m;i++)
       ^