import java.util.*;
import java.lang.*;
import java.io.*;
class Depo
{
{
double n, a;
Scanner in
= new Scanner
(System.
in); n=in.nextDouble();
for(int i=1; i <=n; i++){
a=in.nextDouble();
if(i%2 != 0){
a*=-1;
}
}
}
}
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