\displaystyle V_A=0,\ V_B=2+(V_A-2)\times\frac{10k+40k}{10k}=-8V

\displaystyle V_C=0,\ V_D=3,\ V_E=3V,\ V_F=3\times\frac{20k+12k}{12k}=8V

node C (KVL) \displaystyle \frac{V_C-V_B}{40k}+\frac{V_C-V_F}{80k}=\frac{V_0-V_C}{100k}

\displaystyle V_0=10V