Consider the following cell:

Pt|H2(g,1atm)|H+(aq,?M)||Ag+(aq1M)|Ag(s)
If the voltage of this cell is 1.04V at 25C and the standard potential of the Ag+/Ag couple is .8V, calculate the hydrogen ion concentration in the anode compartment.
I just need help setting up the problem, i believe i am suppose to be using Nernst