---

.model small
.data

n dw 25
i dw 1
flag dw 0

.code
start:

    mov ax, @data
    mov ds, ax

    mov cx, n

m1:
    mov ax, i
    mul i

    cmp ax, n
    je yes

    inc i
    loop m1

    jmp finish

yes:
    mov flag, 1

finish:
    mov ax, 4C00h
    int 21h

end start