import java.util.*;
import java.lang.*;
import java.io.*;
import java.math.*;
class Coordinates{
Scanner read
= new Scanner
(System.
in); double x = read.nextDouble();
double y = read.nextDouble();
double u;
if((y
>= x
*x
) && (y
<= Math.
exp(-x
)) && (y
<= Math.
exp(x
))) u = x+y;
else
u = x-y;
}
}
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