Function at 0x6bc0b0
Capabilities:
Packed with generic packer
Resolve function by parsing pe exports

Disassembly:
pushal
mov esi, section.L_xiBS
lea edi, [esi - 0x21b000]
push edi
mov ebp, esp
lea ebx, [esp - 0x3e80]
xor eax, eax
push eax
cmp esp, ebx
jne 0x6bc0c8
inc esi
inc esi
push ebx
push 0x2ba09b
push edi
add ebx, 4
push ebx
push 0xa00ae
push esi
add ebx, 4
push ebx
push eax
mov dword [ebx], 0x20003
push ebp
push edi
push esi
push ebx
sub esp, 0x7c
mov edx, dword [esp + 0x90]
mov dword [esp + 0x74], 0
mov byte [esp + 0x73], 0
mov ebp, dword [esp + 0x9c]
lea eax, [edx + 4]
mov dword [esp + 0x78], eax
mov eax, 1
movzx ecx, byte [edx + 2]
mov ebx, eax
shl ebx, cl
mov ecx, ebx
dec ecx
mov dword [esp + 0x6c], ecx
movzx ecx, byte [edx + 1]
shl eax, cl
dec eax
mov dword [esp + 0x68], eax
mov eax, dword [esp + 0xa8]
movzx esi, byte [edx]
mov dword [ebp], 0
mov dword [esp + 0x60], 0
mov dword [eax], 0
mov eax, 0x300
mov dword [esp + 0x64], esi
mov dword [esp + 0x5c], 1
mov dword [esp + 0x58], 1
mov dword [esp + 0x54], 1
mov dword [esp + 0x50], 1
movzx ecx, byte [edx + 1]
add ecx, esi
shl eax, cl
lea ecx, [eax + 0x736]
cmp dword [esp + 0x74], ecx
jae 0x6bc19d
mov eax, dword [esp + 0x78]
mov word [eax], 0x400
add eax, 2
loop 0x6bc193
mov ebx, dword [esp + 0x94]
xor edi, edi
mov dword [esp + 0x48], 0xffffffff
mov edx, ebx
add edx, dword [esp + 0x98]
mov dword [esp + 0x4c], edx
xor edx, edx
cmp ebx, dword [esp + 0x4c]
je 0x6bcb43
movzx eax, byte [ebx]
shl edi, 8
inc edx
inc ebx
or edi, eax
cmp edx, 4
jle 0x6bc1bd
mov ecx, dword [esp + 0xa4]
cmp dword [esp + 0x74], ecx
jae 0x6bcb4b
mov esi, dword [esp + 0x74]
and esi, dword [esp + 0x6c]
mov eax, dword [esp + 0x60]
mov edx, dword [esp + 0x78]
shl eax, 4
mov dword [esp + 0x44], esi
add eax, esi
cmp dword [esp + 0x48], 0xffffff
lea ebp, [edx + eax*2]
ja 0x6bc225
cmp ebx, dword [esp + 0x4c]
je 0x6bcb43
shl dword [esp + 0x48], 8
movzx eax, byte [ebx]
shl edi, 8
inc ebx
or edi, eax
mov eax, dword [esp + 0x48]
mov dx, word [ebp]
shr eax, 0xb
movzx ecx, dx
imul eax, ecx
cmp edi, eax
jae 0x6bc41b
mov dword [esp + 0x48], eax
mov eax, 0x800
sub eax, ecx
mov cl, byte [esp + 0x64]
sar eax, 5
mov esi, 1
lea eax, [edx + eax]
movzx edx, byte [esp + 0x73]
mov word [ebp], ax
mov eax, dword [esp + 0x74]
and eax, dword [esp + 0x68]
mov ebp, dword [esp + 0x78]
shl eax, cl
mov ecx, 8
sub ecx, dword [esp + 0x64]
sar edx, cl
add eax, edx
imul eax, eax, 0x600
cmp dword [esp + 0x60], 6
lea eax, [ebp + eax + 0xe6c]
mov dword [esp + 0x14], eax
jle 0x6bc362
mov eax, dword [esp + 0x74]
sub eax, dword [esp + 0x5c]
mov edx, dword [esp + 0xa0]
movzx eax, byte [edx + eax]
mov dword [esp + 0x40], eax
shl dword [esp + 0x40], 1
mov ecx, dword [esp + 0x40]
lea edx, [esi + esi]
mov ebp, dword [esp + 0x14]
and ecx, 0x100
cmp dword [esp + 0x48], 0xffffff
lea eax, [ebp + ecx*2]
mov dword [esp + 0x3c], ecx
lea ebp, [eax + edx]
ja 0x6bc2f1
cmp ebx, dword [esp + 0x4c]
je 0x6bcb43
shl dword [esp + 0x48], 8
movzx eax, byte [ebx]
shl edi, 8
inc ebx
or edi, eax
mov eax, dword [esp + 0x48]
mov cx, word [ebp + 0x200]
shr eax, 0xb
movzx esi, cx
imul eax, esi
cmp edi, eax
jae 0x6bc32c
mov dword [esp + 0x48], eax
mov eax, 0x800
sub eax, esi
mov esi, edx
sar eax, 5
cmp dword [esp + 0x3c], 0
lea eax, [ecx + eax]
mov word [ebp + 0x200], ax
je 0x6bc34c
jmp 0x6bc35a
sub dword [esp + 0x48], eax
sub edi, eax
mov eax, ecx
lea esi, [edx + 1]
shr ax, 5
sub cx, ax
cmp dword [esp + 0x3c], 0
mov word [ebp + 0x200], cx
je 0x6bc35a
cmp esi, 0xff
jle 0x6bc2af
jmp 0x6bc3d3
cmp esi, 0xff
jg 0x6bc3d3
lea edx, [esi + esi]
mov ebp, dword [esp + 0x14]
add ebp, edx
cmp dword [esp + 0x48], 0xffffff
ja 0x6bc38d
cmp ebx, dword [esp + 0x4c]
je 0x6bcb43
shl dword [esp + 0x48], 8
movzx eax, byte [ebx]
shl edi, 8
inc ebx
or edi, eax
mov eax, dword [esp + 0x48]
mov cx, word [ebp]
shr eax, 0xb
movzx esi, cx
imul eax, esi
cmp edi, eax
jae 0x6bc3bb
mov dword [esp + 0x48], eax
mov eax, 0x800
sub eax, esi
mov esi, edx
sar eax, 5
lea eax, [ecx + eax]
mov word [ebp], ax
jmp 0x6bc35a
sub dword [esp + 0x48], eax
sub edi, eax
mov eax, ecx
lea esi, [edx + 1]
shr ax, 5
sub cx, ax
mov word [ebp], cx
jmp 0x6bc35a
mov edx, dword [esp + 0x74]
mov eax, esi
mov ecx, dword [esp + 0xa0]
mov byte [esp + 0x73], al
mov byte [edx + ecx], al
inc edx
cmp dword [esp + 0x60], 3
mov dword [esp + 0x74], edx
jg 0x6bc400
mov dword [esp + 0x60], 0
jmp 0x6bcb1b
cmp dword [esp + 0x60], 9
jg 0x6bc411
sub dword [esp + 0x60], 3
jmp 0x6bcb1b
sub dword [esp + 0x60], 6
jmp 0x6bcb1b
mov ecx, dword [esp + 0x48]
sub edi, eax
mov esi, dword [esp + 0x60]
sub ecx, eax
mov eax, edx
shr ax, 5
sub dx, ax
cmp ecx, 0xffffff
mov word [ebp], dx
mov ebp, dword [esp + 0x78]
lea esi, [ebp + esi*2]
mov dword [esp + 0x38], esi
ja 0x6bc45e
cmp ebx, dword [esp + 0x4c]
je 0x6bcb43
movzx eax, byte [ebx]
shl edi, 8
shl ecx, 8
inc ebx
or edi, eax
mov ebp, dword [esp + 0x38]
mov eax, ecx
shr eax, 0xb
mov dx, word [ebp + 0x180]
movzx ebp, dx
imul eax, ebp
cmp edi, eax
jae 0x6bc4ca
mov esi, eax
mov eax, 0x800
sub eax, ebp
mov ebp, dword [esp + 0x58]
sar eax, 5
mov ecx, dword [esp + 0x54]
lea eax, [edx + eax]
mov edx, dword [esp + 0x38]
mov dword [esp + 0x50], ecx
mov ecx, dword [esp + 0x78]
mov word [edx + 0x180], ax
mov eax, dword [esp + 0x5c]
mov dword [esp + 0x54], ebp
mov dword [esp + 0x58], eax
xor eax, eax
cmp dword [esp + 0x60], 6
setg al
add ecx, 0x664
lea eax, [eax + eax*2]
mov dword [esp + 0x60], eax
jmp 0x6bc73e
mov esi, ecx
sub edi, eax
sub esi, eax
mov eax, edx
shr ax, 5
mov ecx, dword [esp + 0x38]
sub dx, ax
cmp esi, 0xffffff
mov word [ecx + 0x180], dx
ja 0x6bc502
cmp ebx, dword [esp + 0x4c]
je 0x6bcb43
movzx eax, byte [ebx]
shl edi, 8
shl esi, 8
inc ebx
or edi, eax
mov ebp, dword [esp + 0x38]
mov edx, esi
shr edx, 0xb
mov cx, word [ebp + 0x198]
movzx eax, cx
imul edx, eax
cmp edi, edx
jae 0x6bc603
mov ebp, 0x800
mov esi, edx
sub ebp, eax
mov dword [esp + 0x34], 0x800
mov eax, ebp
sar eax, 5
lea eax, [ecx + eax]
mov ecx, dword [esp + 0x38]
mov word [ecx + 0x198], ax
mov eax, dword [esp + 0x60]
mov ecx, dword [esp + 0x44]
shl eax, 5
add eax, dword [esp + 0x78]
cmp edx, 0xffffff
lea ebp, [eax + ecx*2]
ja 0x6bc574
cmp ebx, dword [esp + 0x4c]
je 0x6bcb43
movzx eax, byte [ebx]
shl edi, 8
shl esi, 8
inc ebx
or edi, eax
mov dx, word [ebp + 0x1e0]
mov eax, esi
shr eax, 0xb
movzx ecx, dx
imul eax, ecx
cmp edi, eax
jae 0x6bc5ea
sub dword [esp + 0x34], ecx
sar dword [esp + 0x34], 5
mov esi, dword [esp + 0x34]
mov dword [esp + 0x48], eax
cmp dword [esp + 0x74], 0
lea eax, [edx + esi]
mov word [ebp + 0x1e0], ax
je 0x6bcb43
xor eax, eax
cmp dword [esp + 0x60], 6
mov ebp, dword [esp + 0xa0]
mov edx, dword [esp + 0x74]
setg al
lea eax, [eax + eax + 9]
mov dword [esp + 0x60], eax
mov eax, dword [esp + 0x74]
sub eax, dword [esp + 0x5c]
mov al, byte [ebp + eax]
mov byte [esp + 0x73], al
mov byte [edx + ebp], al
inc edx
mov dword [esp + 0x74], edx
jmp 0x6bcb1b
sub esi, eax
sub edi, eax
mov eax, edx
shr ax, 5
sub dx, ax
mov word [ebp + 0x1e0], dx
jmp 0x6bc722
mov eax, ecx
sub esi, edx
shr ax, 5
mov ebp, dword [esp + 0x38]
sub cx, ax
sub edi, edx
cmp esi, 0xffffff
mov word [ebp + 0x198], cx
ja 0x6bc639
cmp ebx, dword [esp + 0x4c]
je 0x6bcb43
movzx eax, byte [ebx]
shl edi, 8
shl esi, 8
inc ebx
or edi, eax
mov ecx, dword [esp + 0x38]
mov eax, esi
shr eax, 0xb
mov dx, word [ecx + 0x1b0]
movzx ecx, dx
imul eax, ecx
cmp edi, eax
jae 0x6bc676
mov esi, eax
mov eax, 0x800
sub eax, ecx
mov ebp, dword [esp + 0x38]
sar eax, 5
lea eax, [edx + eax]
mov word [ebp + 0x1b0], ax
mov eax, dword [esp + 0x58]
jmp 0x6bc716
mov ecx, esi
sub edi, eax
sub ecx, eax
mov eax, edx
shr ax, 5
sub dx, ax
mov eax, dword [esp + 0x38]
cmp ecx, 0xffffff
mov word [eax + 0x1b0], dx
ja 0x6bc6ae
cmp ebx, dword [esp + 0x4c]
je 0x6bcb43
movzx eax, byte [ebx]
shl edi, 8
shl ecx, 8
inc ebx
or edi, eax
mov esi, dword [esp + 0x38]
mov eax, ecx
shr eax, 0xb
mov dx, word [esi + 0x1c8]
movzx ebp, dx
imul eax, ebp
cmp edi, eax
jae 0x6bc6e8
mov esi, eax
mov eax, 0x800
sub eax, ebp
mov ebp, dword [esp + 0x38]
sar eax, 5
lea eax, [edx + eax]
mov word [ebp + 0x1c8], ax
mov eax, dword [esp + 0x54]
jmp 0x6bc70e
mov esi, ecx
sub edi, eax
sub esi, eax
mov eax, edx
shr ax, 5
sub dx, ax
mov eax, dword [esp + 0x38]
mov word [eax + 0x1c8], dx
mov edx, dword [esp + 0x54]
mov eax, dword [esp + 0x50]
mov dword [esp + 0x50], edx
mov ecx, dword [esp + 0x58]
mov dword [esp + 0x54], ecx
mov ebp, dword [esp + 0x5c]
mov dword [esp + 0x5c], eax
mov dword [esp + 0x58], ebp
xor eax, eax
cmp dword [esp + 0x60], 6
mov ecx, dword [esp + 0x78]
setg al
add ecx, 0xa68
lea eax, [eax + eax*2 + 8]
mov dword [esp + 0x60], eax
cmp esi, 0xffffff
ja 0x6bc75c
cmp ebx, dword [esp + 0x4c]
je 0x6bcb43
movzx eax, byte [ebx]
shl edi, 8
shl esi, 8
inc ebx
or edi, eax
mov dx, word [ecx]
mov eax, esi
shr eax, 0xb
movzx ebp, dx
imul eax, ebp
cmp edi, eax
jae 0x6bc79d
mov dword [esp + 0x48], eax
mov eax, 0x800
sub eax, ebp
shl dword [esp + 0x44], 4
sar eax, 5
mov dword [esp + 0x2c], 0
lea eax, [edx + eax]
mov word [ecx], ax
mov eax, dword [esp + 0x44]
lea ecx, [ecx + eax + 4]
mov dword [esp + 0x10], ecx
jmp 0x6bc80f
sub esi, eax
sub edi, eax
mov eax, edx
shr ax, 5
sub dx, ax
cmp esi, 0xffffff
mov word [ecx], dx
ja 0x6bc7cb
cmp ebx, dword [esp + 0x4c]
je 0x6bcb43
movzx eax, byte [ebx]
shl edi, 8
shl esi, 8
inc ebx
or edi, eax
mov dx, word [ecx + 2]
mov eax, esi
shr eax, 0xb
movzx ebp, dx
imul eax, ebp
cmp edi, eax
jae 0x6bc819
mov dword [esp + 0x48], eax
mov eax, 0x800
sub eax, ebp
shl dword [esp + 0x44], 4
sar eax, 5
mov dword [esp + 0x2c], 8
lea eax, [edx + eax]
mov edx, dword [esp + 0x44]
mov word [ecx + 2], ax
lea ecx, [ecx + edx + 0x104]
mov dword [esp + 0x10], ecx
mov dword [esp + 0x30], 3
jmp 0x6bc848
sub esi, eax
sub edi, eax
mov eax, edx
mov dword [esp + 0x48], esi
shr ax, 5
mov dword [esp + 0x2c], 0x10
sub dx, ax
mov dword [esp + 0x30], 8
mov word [ecx + 2], dx
add ecx, 0x204
mov dword [esp + 0x10], ecx
mov ecx, dword [esp + 0x30]
mov edx, 1
mov dword [esp + 0x28], ecx
lea ebp, [edx + edx]
mov esi, dword [esp + 0x10]
add esi, ebp
cmp dword [esp + 0x48], 0xffffff
ja 0x6bc880
cmp ebx, dword [esp + 0x4c]
je 0x6bcb43
shl dword [esp + 0x48], 8
movzx eax, byte [ebx]
shl edi, 8
inc ebx
or edi, eax
mov eax, dword [esp + 0x48]
mov dx, word [esi]
shr eax, 0xb
movzx ecx, dx
imul eax, ecx
cmp edi, eax
jae 0x6bc8ac
mov dword [esp + 0x48], eax
mov eax, 0x800
sub eax, ecx
sar eax, 5
lea eax, [edx + eax]
mov edx, ebp
mov word [esi], ax
jmp 0x6bc8c1
sub dword [esp + 0x48], eax
sub edi, eax
mov eax, edx
shr ax, 5
sub dx, ax
mov word [esi], dx
lea edx, [ebp + 1]
mov esi, dword [esp + 0x28]
dec esi
mov dword [esp + 0x28], esi
jne 0x6bc855
mov cl, byte [esp + 0x30]
mov eax, 1
shl eax, cl
sub edx, eax
add edx, dword [esp + 0x2c]
cmp dword [esp + 0x60], 3
mov dword [esp + 0xc], edx
jg 0x6bcad3
add dword [esp + 0x60], 7
cmp edx, 3
mov eax, edx
jle 0x6bc8fd
mov eax, 3
mov esi, dword [esp + 0x78]
shl eax, 7
mov dword [esp + 0x24], 6
lea eax, [esi + eax + 0x360]
mov dword [esp + 8], eax
mov eax, 1
lea ebp, [eax + eax]
mov esi, dword [esp + 8]
add esi, ebp
cmp dword [esp + 0x48], 0xffffff
ja 0x6bc947
cmp ebx, dword [esp + 0x4c]
je 0x6bcb43
shl dword [esp + 0x48], 8
movzx eax, byte [ebx]
shl edi, 8
inc ebx
or edi, eax
mov eax, dword [esp + 0x48]
mov dx, word [esi]
shr eax, 0xb
movzx ecx, dx
imul eax, ecx
cmp edi, eax
jae 0x6bc973
mov dword [esp + 0x48], eax
mov eax, 0x800
sub eax, ecx
sar eax, 5
lea eax, [edx + eax]
mov word [esi], ax
mov eax, ebp
jmp 0x6bc988
sub dword [esp + 0x48], eax
sub edi, eax
mov eax, edx
shr ax, 5
sub dx, ax
lea eax, [ebp + 1]
mov word [esi], dx
mov ebp, dword [esp + 0x24]
dec ebp
mov dword [esp + 0x24], ebp
jne 0x6bc91c
lea edx, [eax - 0x40]
cmp edx, 3
mov dword [esp], edx
jle 0x6bcac9
mov eax, edx
mov esi, edx
sar eax, 1
and esi, 1
lea ecx, [eax - 1]
or esi, 2
cmp edx, 0xd
mov dword [esp + 0x20], ecx
jg 0x6bc9d6
mov ebp, dword [esp + 0x78]
shl esi, cl
add edx, edx
mov dword [esp], esi
lea eax, [ebp + esi*2]
sub eax, edx
add eax, 0x55e
mov dword [esp + 4], eax
jmp 0x6bca2c
lea edx, [eax - 5]
cmp dword [esp + 0x48], 0xffffff
ja 0x6bc9fb
cmp ebx, dword [esp + 0x4c]
je 0x6bcb43
shl dword [esp + 0x48], 8
movzx eax, byte [ebx]
shl edi, 8
inc ebx
or edi, eax
shr dword [esp + 0x48], 1
add esi, esi
cmp edi, dword [esp + 0x48]
jb 0x6bca0e
sub edi, dword [esp + 0x48]
or esi, 1
dec edx
jne 0x6bc9d9
mov eax, dword [esp + 0x78]
shl esi, 4
mov dword [esp], esi
add eax, 0x644
mov dword [esp + 0x20], 4
mov dword [esp + 4], eax
mov dword [esp + 0x1c], 1
mov eax, 1
mov ebp, dword [esp + 4]
add eax, eax
mov dword [esp + 0x18], eax
add ebp, eax
cmp dword [esp + 0x48], 0xffffff
ja 0x6bca67
cmp ebx, dword [esp + 0x4c]
je 0x6bcb43
shl dword [esp + 0x48], 8
movzx eax, byte [ebx]
shl edi, 8
inc ebx
or edi, eax
mov eax, dword [esp + 0x48]
mov dx, word [ebp]
shr eax, 0xb
movzx esi, dx
imul eax, esi
cmp edi, eax
jae 0x6bca97
mov dword [esp + 0x48], eax
mov eax, 0x800
sub eax, esi
sar eax, 5
lea eax, [edx + eax]
mov word [ebp], ax
mov eax, dword [esp + 0x18]
jmp 0x6bcab6
sub dword [esp + 0x48], eax
sub edi, eax
mov eax, edx
shr ax, 5
sub dx, ax
mov eax, dword [esp + 0x18]
mov word [ebp], dx
mov edx, dword [esp + 0x1c]
inc eax
or dword [esp], edx
mov ecx, dword [esp + 0x20]
shl dword [esp + 0x1c], 1
dec ecx
mov dword [esp + 0x20], ecx
jne 0x6bca39
mov esi, dword [esp]
inc esi
mov dword [esp + 0x5c], esi
je 0x6bcb2c
mov ecx, dword [esp + 0xc]
mov ebp, dword [esp + 0x74]
add ecx, 2
cmp dword [esp + 0x5c], ebp
ja 0x6bcb43
mov eax, dword [esp + 0xa0]
mov edx, ebp
sub eax, dword [esp + 0x5c]
add edx, dword [esp + 0xa0]
lea esi, [eax + ebp]
mov al, byte [esi]
inc esi
mov byte [esp + 0x73], al
mov byte [edx], al
inc edx
inc dword [esp + 0x74]
dec ecx
je 0x6bcb1b
mov ebp, dword [esp + 0xa4]
cmp dword [esp + 0x74], ebp
jb 0x6bcafb
jmp 0x6bcb2c
mov eax, dword [esp + 0xa4]
cmp dword [esp + 0x74], eax
jb 0x6bc1e7
cmp dword [esp + 0x48], 0xffffff
ja 0x6bcb4b
cmp ebx, dword [esp + 0x4c]
mov eax, 1
je 0x6bcb6a
jmp 0x6bcb4a
mov eax, 1
jmp 0x6bcb6a
inc ebx
sub ebx, dword [esp + 0x94]
xor eax, eax
mov edx, dword [esp + 0x9c]
mov ecx, dword [esp + 0x74]
mov dword [edx], ebx
mov ebx, dword [esp + 0xa8]
mov dword [ebx], ecx
add esp, 0x7c
pop ebx
pop esi
pop edi
pop ebp
add esi, dword [ebx - 4]
add edi, dword [ebx - 8]
xor eax, eax
lea ecx, [esp - 0x100]
mov esp, ebp
push eax
cmp esp, ecx
jne 0x6bcb82
mov esp, ebp
xor ecx, ecx
pop esi
mov edi, esi
mov ecx, 0x3afc
mov al, byte [edi]
inc edi
sub al, 0xe8
cmp al, 1
ja 0x6bcb93
cmp byte [edi], 0x17
jne 0x6bcb93
mov eax, dword [edi]
mov bl, byte [edi + 4]
shr ax, 8
rol eax, 0x10
xchg ah, al
sub eax, edi
sub bl, 0xe8
add eax, esi
mov dword [edi], eax
add edi, 5
mov al, bl
loop 0x6bcb98
lea edi, [esi + 0x2b7000]
mov eax, dword [edi]
or eax, eax
je 0x6bcc10
mov ebx, dword [edi + 4]
lea eax, [eax + esi + 0x2bc29c]
add ebx, esi
push eax
add edi, 8
call dword [esi + 0x2bc418]
xchg ebp, eax
mov al, byte [edi]
inc edi
or al, al
je 0x6bcbc5
mov ecx, edi
jns 0x6bcbf4
movzx eax, word [edi]
inc edi
push eax
inc edi
mov ecx, 0xaef24857
push edi
dec eax
repne scasb al, byte es:[edi]
push ebp
call dword [esi + 0x2bc420]
or eax, eax
je 0x6bcc0a
mov dword [ebx], eax
add ebx, 4
jmp 0x6bcbe2
call dword [esi + 0x2bc41c]
mov ebp, dword [esi + 0x2bc424]
lea edi, [esi - 0x1000]
mov ebx, 0x1000
push eax
push esp
push 4
push ebx
push edi
call ebp
lea eax, [edi + 0x217]
and byte [eax], 0x7f
and byte [eax + 0x28], 0x7f
pop eax
push eax
push esp
push eax
push ebx
push edi
call ebp
pop eax
popal
lea eax, [esp - 0x80]
push 0
cmp esp, eax
jne 0x6bcc44
sub esp, 0xffffff80
jmp 0x4789b1