////Given
W=3.45                                     //ev
h=6.63*10**-34                              //Js
c=3*10**8                                   //m/s
e=1.6*10**-19

//Calculation
lembda=(h*c)/(W*e)

//Result
printf("\n Maximum wavelength of photon is  %0.0f A",lembda*10**10)