GES clusters NGC 2243 and Trumpler 23: log g-T_eff diagrams with PISA isochrones 3.7, 4.0, 4.3, and 4.5 Gyr and 0.7, 0.8, 0.9, and 1.0 Gyr, respectively (left panels), and member stars beyond the FDU, A(Li) vs. [C/N] (central panel), and [C/N] abundance vs. T_eff (right panel). Stars with A(Li) > 0.4 are shown with red circles, stars with A(Li) < 0.4 with blue circles, stars with upper limit measurements of A(Li) are indicated with empty circles, and main sequence, subgiant stars or stars without C and N are shown with grey circles. The green star represents the position of the RGB bump.