The reduced cross sections for e(+)p deep inelastic scattering have been measured with the ZEUS detector at HERA at three different center-of-mass energies, 318, 251 and 225 GeV. The cross sections, measured double differentially in Bjorken x and the virtuality, Q(2), were obtained in the region 0.13 <= y <= 0.75, where y denotes the inelasticity and 5 <= Q(2) <= 110 GeV2. The proton structure functions F-2 and F-L were extracted from the measured cross sections.