Family vacation expenses

budget=float(input())
nights=int(input())
night_price=float(input())
extra_expenses=int(input())

if nights>7:
  night_price=night_price*0.95
else:
    night_price=night_price

left=night_price*nights+budget*extra_expenses/100

if left<=budget:
  print('Ivanovi will be left with', '%.2f'%(budget-left), 'leva after vacation.')
else:
  print('%.2f'%-(budget-left), 'leva needed.')