Electrochemistry

If standard reduction potential $\left(E^{\circ}\right)$ of $\left(\mathrm{Ni}_{(\mathrm{aq})}^{+2} \mid \mathrm{Ni}_{(\mathrm{s})}\right)$ and $\left(\mathrm{Al}_{(\mathrm{aq})}^{+3} \mid \mathrm{Al}_{(\mathrm{s})}\right)$ are -0.25 V and -1.66 V respectively. What is standard emf of cell reaction $2 \mathrm{Al}_{(\mathrm{s})}+3 \mathrm{Ni}_{(\mathrm{aq})}^{+2} \longrightarrow 2 \mathrm{Al}_{(\mathrm{aq})}^{+3}+3 \mathrm{Ni}_{(\mathrm{s})}$