An electric metamaterial is constructed as stratified layers of silver and glass. The permittivity for the glass is -glass = 2.25-0.5i and for the silver _Ag = -4.5 -0.15i with a filling factor f= 25% for the silver. The effective electron concentration and mass are respectively N_eff = 1.5x10^26 m^3 meff =2.5m_0 where m_o is electron mass. Calculate the resonant frequency of the metamaterial if its oscillator strength is twice the resonant frequency.