06. Fishland

skumriq = float(input())
caca = float(input())
palamud = float(input())
safrid = float(input())
midi = int(input())

palamud_price = palamud + (skumriq * 0.6)
palamud_sum = palamud * palamud_price

safrid_price = safrid + (caca * 0.8)
safrid_sum = safrid * safrid_price

midi_sum = midi * 7.50

print(palamud_sum + safrid_sum + midi_sum)