/* package whatever; // don't place package name! */
import java.util.*;
import java.lang.*;
import java.io.*;
/* Name of the class has to be "Main" only if the class is public. */
class Ideone
{
line = br.readLine();
String [] nums
= line.
split(" "); List<Integer> arr = new ArrayList<Integer>();
for (int i = 0; i < N; i++) {
arr.
add(Integer.
parseInt(nums
[i
])); }
int start = 0;
int end = arr.size()-1;
int m = 0;
int prev = arr.get(start);
boolean takeMax = true;
int curr;
while(start<=end){
if(takeMax)
curr = arr.get(end);
else
curr = arr.get(start);
takeMax=!takeMax;
m
+=(Math.
abs(prev
-curr
)); prev=curr;
start++;
end--;
}
}
}
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