The point charges \(+q\), \(-q\), \(-q\), \(+q\), \(+Q\) and \(-q\) are placed at the vertices of a regular hexagon ABCDEF as shown in the figure.

The electric field at the centre of the hexagon 'O' due to the five charges at A, B, C, D and F is thrice the electric field at centre 'O' due to charge \(+Q\) at E alone. The value of Q is