program main
IMPLICIT none
    INTEGER :: p=1,i,j,x,n
    REAL :: s=0,t,f
    PRINT *,"ENTER 2 NUMBERS"
    read *,x,N
    DO i=1,N
    f=1
    DO j=1,i
    f=f*J
    ENDDO
    t=x**i/f
    t=t*p
    PRINT *,t
    s=s+t
    p=p*(-1)
    ENDDO
    PRINT *,"Sum =",s
end program main