B
1
⋯
B
s
总和
A
1
p
11
⋯
p
1
s
p
1
⋅
⋮
⋮
⋮
⋮
A
r
p
r
1
⋯
p
r
s
p
r
⋅
总和
p
⋅
1
⋯
p
⋅
s
1