! 3.4.f90
! 2014-08-16
!
! r  : rate, 利率
! n  : number of periods, 期間
! ma : maximum amount, 最大金額
! a  : monthly payments, 毎月の支払額
! f  : the total fees, 総手数料
! p  : present value, 現在価値

implicit none
integer :: n
real(8) :: a, f, ma, p, r

! input
r = 0.08083 / 12.0
n = 30 * 12
ma = 203150.0
p = ma

! calculate
a = r * (1.0 + r)**n * p / ((1.0 + r)**n - 1)
a = int(a)

! input
r = 0.07875 / 12.0
n = 30 * 12
! calculate
p = a / r * (1.0 - 1.0 / (1.0 + r)**n)
f = p - ma

! output
write(*,'(a25,i10,a)') 'monthly payments is ',int(a),' ($)'
write(*,'(a25,i10,a)') 'total initial balance is ', int(p), ' ($)'
write(*,'(a25,i10,a)') 'the total fees is ', int(f),' ($)'

stop
end