import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Scanner;
public class Main
{
public static void main(String[]args)
{
BufferedReader buf=null;
buf=new BufferedReader(new InputStreamReader(System.in));
String str=null;
try {
int a= Integer.parseInt(buf.readLine());
double[]array=new double[a];
double[]dp=new double[a+1];
dp[0]=0;
double max=0;
for(int i=0;i<a;i++){
array[i]=Double.parseDouble(buf.readLine());
}
int begin=0;
for(int i=1;i<a;i++){
dp[i]=dp[i-1]+array[i]-array[i-1];
if(dp[i]==180){max=180;
System.out.println(String.format("%.8f",max)+"\n");return;}
else if(dp[i]>180){ if(360-dp[i]>max)max=360-dp[i];
while(dp[i]>180){ if(360-dp[i]>max)max=360-dp[i];
dp[i]=dp[i]-(array[begin+1]-array[begin]);
begin++;
} if(dp[i]==180)
{max=180;
System.out.println(String.format("%.8f",max)+"\n");return;}
else if(dp[i]<180){ if(dp[i]>max)max=dp[i];
}
}else if(dp[i]<180){ if(dp[i]>max)max=dp[i];
}
}
System.out.println(String.format("%.8f",max)+"\n");
} catch (IOException e) {
e.printStackTrace();
}
System.out.println();
}
}