%include "io.inc"

section .bss
    n       resd 1
    k       resd 1
    res     resd 1
    i       resd 1
    Cn      resd 1
    Ck      resd 1
    Cres    resd 1

section .data
    m       dd  -1
    r       dd   0

section .text
global CMAIN
CMAIN:
    GET_UDEC 4, [n]
    GET_UDEC 4, [k]

    mov eax, [n]    ; i = n
    cmp eax, 2      ;
    jb  .EXIT_1     ; if (n < 2) { return k <= 1 & (n != 0) & ~k; }

    mov ebx, [m]
.L1:
    inc ebx         ; m++
    shr eax, 1      ; i >>= 1
    jnz .L1
    mov [m], ebx

    mov eax, 1      ;
    mov ecx, [m]    ;
    dec ecx         ;
    shl eax, cl     ; i = 1 << (m - 1);

    mov ebx, [r]
    test eax, eax
    jz .BL2         ; if (i == 0) goto BL2;
    test eax, [n]   ; n & i
    jnz .BL2
.L2:
    inc ebx         ; r++
    shr eax, 1      ; i >>= 1
    jz .BL2
    test eax, [n]   ; n & i
    jz .L2

.BL2:
    mov [r], ebx

    mov eax, [m]    ;
    mov [Cn], eax   ; Cn = m;

    mov eax, [k]    ;
    inc eax         ;
    mov [Ck], eax   ; Ck = k + 1;

    cmp eax, [Cn]   ;
    ja .M1          ; if (Ck > Cn) goto M1;
    shl eax, 1
    cmp eax, [n]
    jbe .S1         ; if (Ck * 2 <= n) goto S1;

    mov eax, [Cn]   ;
    sub eax, [Ck]   ;
    mov [Ck], eax   ; Ck = Cn - Ck;
.S1:
    test eax, eax
    jnz .S2         ; if (Ck != 0) goto S2;
    mov eax, 1      ;
    mov [res], eax  ; res = 1
    jmp .M1         ; if (Ck == 0) { res = 1; goto M1; }



.S2:
    mov eax, [Cn]   ; res = Cn
    mov ebx, 2      ; i = 2
    cmp ebx, [Ck]   ; i - Ck
    ja .BL3         ; if (i > Ck) goto BL3;


.L3:
    mov ecx, [Cn]   ;
    sub ecx, ebx    ; Cn - i
    inc ecx         ; Cn - i + 1
    mul ecx         ; res *= (Cn - i + 1);

    div ebx         ; res /= i
    inc ebx         ; i++
    cmp ebx, [Ck]   ; i - Ck
    jbe .L3

.BL3:
    mov [res], eax


.M1:
    mov ecx, [m]    ;
    mov eax, 1      ;
    shl eax, cl     ;
    xor eax, [n]    ;
    mov [n], eax    ; n ^= (1 << m);

    mov eax, [k]    ;
    sub eax, [r]    ;
    mov [k], eax    ; k -= r;

    mov eax, [m]    ;
    dec eax         ;
    sub eax, [r]    ;
    mov [m], eax    ; m -= (r + 1);

    xor eax, eax    ;
    mov [r], eax    ; r = 0

    inc eax         ;
    mov ecx, [m]    ;
    dec ecx         ;
    shl eax, cl     ; i = 1 << (m - 1);

    mov ebx, [r]
    test eax, eax
    jz .BL4
    test eax, [n]   ; n & i
    jnz .BL4
.L4:
    inc ebx         ; r++
    shr eax, 1      ; i >>= 1
    jz .BL4
    test eax, [n]   ; n & i
    jz .L4

.BL4:
    mov [r], ebx

;PRINT_UDEC 4, res
;NEWLINE
;PRINT_UDEC 4, n
;NEWLINE
;PRINT_UDEC 4, k
;NEWLINE
;PRINT_UDEC 4, r
;NEWLINE

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
.L5:
    mov eax, [n]    ;
    test eax, eax   ; n & n
    jz .EXIT_2      ; if (n == 0) { return res + (k == 0); }

    mov eax, [k]    ;
    test eax, eax   ; k & k
    jz .EXIT_3      ; if (k == 0) { return res + (n == (1 << (m + 1)) - 1); }

    mov eax, [m]    ;
    mov [Cn], eax   ; Cn = m;

    mov eax, [k]    ;
    dec eax         ;
    mov [Ck], eax   ; Ck = k - 1;

    cmp eax, [Cn]   ;
    ja  .M2         ; if (Ck > Cn) { goto M2; }

    shl eax, 1      ;
    cmp eax, [n]    ;
    jbe .S3         ; if (Ck * 2 <= n) goto S3;

    mov eax, [Cn]   ;
    sub eax, [Ck]   ;
    mov [Ck], eax   ; if (Ck * 2 > n) { Ck = Cn - Ck; }

.S3:
    test eax, eax
    jnz .S4         ; if (Ck != 0) goto S4;
    mov eax, [res]  ;
    inc eax         ;
    mov [res], eax  ; res += 1
    jmp .M2         ; if (Ck == 0) { res += 1; goto M2; }

.S4:
    mov eax, [Cn]   ; Cres = Cn
    mov ebx, 2      ; i = 2
    cmp ebx, [Ck]   ; i - Ck
    ja .BL6         ; if (i > Ck) goto BL6;
.L6:
    mov ecx, [Cn]
    inc ecx         ; Cn + 1
    sub ecx, ebx    ; Cn - i + 1
    mul ecx         ; Cres *= (Cn - i + 1)
    div ebx         ; Cres /= i
    inc ebx         ; i ++
    cmp ebx, [Ck]   ; i - Ck
    jbe .L6
.BL6:
    add eax, [res]  ;
    mov [res], eax  ; res += Cres;

.M2:
    mov eax, 1      ;
    mov ecx, [m]    ;
    shl eax, cl     ;
    xor eax, [n]    ;
    mov [n], eax    ; n ^= (1 << m);

    mov eax, [k]    ;
    sub eax, [r]    ;
    mov [k], eax    ;k -= r;

    mov eax, [m]    ;
    dec eax         ;
    sub eax, [r]    ;
    mov [m], eax    ; m -= (r + 1);

    xor eax, eax    ;
    mov [r], eax    ; r = 0

    inc eax         ;
    mov ecx, [m]    ;
    dec ecx         ;
    shl eax, cl     ; i = 1 << (m - 1);

    mov ebx, [r]
    test eax, eax
    jz .BL7
    test eax, [n]
    jnz .BL7
.L7:
    inc ebx         ; r++
    shr eax, 1      ; i >>= 1
    jz .BL7
    test eax, [n]   ; n & i
    jz .L7

.BL7:
    mov [r], ebx
    jmp .L5
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;





.EXIT_3:
    ;PRINT_STRING "EXIT 3"
;    NEWLINE

    mov ebx, 1
    mov ecx, [m]    ; m
    inc ecx         ; m + 1
    shl ebx, cl     ; (1 << (m + 1))
    dec ebx         ; (1 << (m + 1)) - 1
    xor eax, eax
    cmp ebx, [n]
    sete al         ; n == (1 << (m + 1)) - 1
    add eax, [res]  ; res + (n == (1 << (m + 1)) - 1)
    jmp .MAIN_EXIT

.EXIT_2:
;    PRINT_STRING "EXIT 2"
;    NEWLINE

    xor eax, eax
    mov ebx, [k]
    test ebx, ebx   ; k & k
    setz al
    add eax, [res]
    jmp .MAIN_EXIT

.EXIT_1:
;    PRINT_STRING "EXIT 1"
;    NEWLINE

    test eax, eax
    cmovz eax, [r]
    jz .MAIN_EXIT
    mov eax, [k]
    cmp eax, 1
    cmova eax, [r]
    ja .MAIN_EXIT
    cmove eax, [r]
    je .MAIN_EXIT
    mov eax, 1

.MAIN_EXIT:
    PRINT_UDEC 4, eax
    xor eax, eax
    ret