题目描述
We call an quadruple of positive integers, $(W,X,Y,Z)$, beautiful if the following condition is true:
$W\oplus X\oplus Y\oplus Z\neq0$
Note: $\theta$ is the bitwise XOR operator.
Given $\mbox{A}$, $\mbox{B}$, $\mbox{C}$, and $\mbox{D}$, count the number of beautiful quadruples of the form $(W,X,Y,Z)$ where the following constraints hold:
$1\leq W\leq A$
$1\leq X\leq B$
$1\leq Y\leq C$
$1\leq z\leq D$
When you count the number of beautiful quadruples, you should consider two quadruples as same if the following are true:
They contain same integers.
Number of times each integers occur in the quadruple is same.
For example $(1,1,1,2)$ and $(1,1,2,1)$ should be considered as same.
Input Format
A single line with four space-separated integers describing the respective values of $\mbox{A}$, $\mbox{B}$, $\mbox{C}$, and $\mbox{D}$.
Constraints
$1\leq A,B,C,D\leq3000$
For $50\%$ of the maximum score, $1\leq A,B,C,D\leq50$
Output Format
Print the number of beautiful quadruples.
Sample Input
1 2 3 4
Sample Output
11
Explanation
There are $\mbox{11}$ beautiful quadruples for this input:
$(1,1,1,2)$
$(1,1,1,3)$
$(1,1,1,4)$
$(1,1,2,3)$
$(1,1,2,4)$
$(1,1,3,4)$
$(1,2,2,2)$
$(1,2,2,3)$
$(1,2,2,4)$
$(1,2,3,3)$
$(1,2,3,4)$
Thus, we print $\mbox{11}$ as our output.
Note that $(1,1,1,2)$ is same as $(1,1,2,1)$.
输入格式
见题面
输出格式
见题面