/in/foo.cc: In function 'void solve()':
/in/foo.cc:7:10: warning: suggest parentheses around assignment used as truth value [-Wparentheses]
  if(a=b*2)
          ^
/in/foo.cc:13:30: error: lvalue required as left operand of assignment
  while(++i<--j&&i<b&&c[i]=c[j])
                              ^
/in/foo.cc:14:12: error: invalid conversion from 'const char*' to 'int' [-fpermissive]
  cout<<(i=b?"Yes":"No")<<endl;
           ~^~~~~~~~~~~