import java.util.Arrays;
import java.util.Scanner;


public class Main {

	public static void main(String[] args) {

    	Scanner parameter = new Scanner(System.in);

    	String[] line1 = parameter.nextLine().split(" ");
        String[] line2 = parameter.nextLine().split(" ");

        double[] doubleNumber = new double[line2.length];

        for (int i = 0; i < line2.length; i++) {

        	doubleNumber[i] = Integer.parseInt(line2[i]);
        }

        Arrays.sort(doubleNumber);

        if (doubleNumber.length == 1) {

        	System.out.println(doubleNumber[0]);
        } else {

        	for (int i = 0; i < doubleNumber.length; i++) {

        		if (i < doubleNumber.length - 1) {

        			doubleNumber[i+1] = (doubleNumber[i] + doubleNumber[i+1]) / 2;
        		} else {

        			System.out.println(doubleNumber[doubleNumber.length - 1]);
        		}
            }
        }
    }
} import java.util.Arrays; Arrays java.util import java.util.Scanner; Scanner java.util public class Main {

	public static void main(String[] args) {

    	Scanner parameter = new Scanner(System.in);

    	String[] line1 = parameter.nextLine().split(" ");
        String[] line2 = parameter.nextLine().split(" ");

        double[] doubleNumber = new double[line2.length];

        for (int i = 0; i < line2.length; i++) {

        	doubleNumber[i] = Integer.parseInt(line2[i]);
        }

        Arrays.sort(doubleNumber);

        if (doubleNumber.length == 1) {

        	System.out.println(doubleNumber[0]);
        } else {

        	for (int i = 0; i < doubleNumber.length; i++) {

        		if (i < doubleNumber.length - 1) {

        			doubleNumber[i+1] = (doubleNumber[i] + doubleNumber[i+1]) / 2;
        		} else {

        			System.out.println(doubleNumber[doubleNumber.length - 1]);
        		}
            }
        }
    }
} Main public static void main(String[] args) {

    	Scanner parameter = new Scanner(System.in);

    	String[] line1 = parameter.nextLine().split(" ");
        String[] line2 = parameter.nextLine().split(" ");

        double[] doubleNumber = new double[line2.length];

        for (int i = 0; i < line2.length; i++) {

        	doubleNumber[i] = Integer.parseInt(line2[i]);
        }

        Arrays.sort(doubleNumber);

        if (doubleNumber.length == 1) {

        	System.out.println(doubleNumber[0]);
        } else {

        	for (int i = 0; i < doubleNumber.length; i++) {

        		if (i < doubleNumber.length - 1) {

        			doubleNumber[i+1] = (doubleNumber[i] + doubleNumber[i+1]) / 2;
        		} else {

        			System.out.println(doubleNumber[doubleNumber.length - 1]);
        		}
            }
        }
    } main {

    	Scanner parameter = new Scanner(System.in);

    	String[] line1 = parameter.nextLine().split(" ");
        String[] line2 = parameter.nextLine().split(" ");

        double[] doubleNumber = new double[line2.length];

        for (int i = 0; i < line2.length; i++) {

        	doubleNumber[i] = Integer.parseInt(line2[i]);
        }

        Arrays.sort(doubleNumber);

        if (doubleNumber.length == 1) {

        	System.out.println(doubleNumber[0]);
        } else {

        	for (int i = 0; i < doubleNumber.length; i++) {

        		if (i < doubleNumber.length - 1) {

        			doubleNumber[i+1] = (doubleNumber[i] + doubleNumber[i+1]) / 2;
        		} else {

        			System.out.println(doubleNumber[doubleNumber.length - 1]);
        		}
            }
        }
    } Scanner parameter = new Scanner(System.in); parameter new Scanner(System.in) String[] line1 = parameter.nextLine().split(" "); line1 parameter.nextLine().split(" ") parameter.nextLine().split parameter.nextLine() parameter.nextLine parameter " " String[] line2 = parameter.nextLine().split(" "); line2 parameter.nextLine().split(" ") parameter.nextLine().split parameter.nextLine() parameter.nextLine parameter " " double[] doubleNumber = new double[line2.length]; doubleNumber new double[line2.length] line2.length line2 line2.length for (int i = 0; i < line2.length; i++) {

        	doubleNumber[i] = Integer.parseInt(line2[i]);
        } int i = 0; int i = 0; i 0 i < line2.length i line2.length line2 line2.length i++ i++ i {

        	doubleNumber[i] = Integer.parseInt(line2[i]);
        } {

        	doubleNumber[i] = Integer.parseInt(line2[i]);
        } doubleNumber[i] = Integer.parseInt(line2[i]) doubleNumber[i] doubleNumber i Integer.parseInt(line2[i]) Integer.parseInt Integer line2[i] line2 i Arrays.sort(doubleNumber) Arrays.sort Arrays doubleNumber if (doubleNumber.length == 1) {

        	System.out.println(doubleNumber[0]);
        } else {

        	for (int i = 0; i < doubleNumber.length; i++) {

        		if (i < doubleNumber.length - 1) {

        			doubleNumber[i+1] = (doubleNumber[i] + doubleNumber[i+1]) / 2;
        		} else {

        			System.out.println(doubleNumber[doubleNumber.length - 1]);
        		}
            }
        } doubleNumber.length == 1 doubleNumber.length doubleNumber doubleNumber.length 1 {

        	System.out.println(doubleNumber[0]);
        } System.out.println(doubleNumber[0]) System.out.println System.out System System.out doubleNumber[0] doubleNumber 0 {

        	for (int i = 0; i < doubleNumber.length; i++) {

        		if (i < doubleNumber.length - 1) {

        			doubleNumber[i+1] = (doubleNumber[i] + doubleNumber[i+1]) / 2;
        		} else {

        			System.out.println(doubleNumber[doubleNumber.length - 1]);
        		}
            }
        } for (int i = 0; i < doubleNumber.length; i++) {

        		if (i < doubleNumber.length - 1) {

        			doubleNumber[i+1] = (doubleNumber[i] + doubleNumber[i+1]) / 2;
        		} else {

        			System.out.println(doubleNumber[doubleNumber.length - 1]);
        		}
            } int i = 0; int i = 0; i 0 i < doubleNumber.length i doubleNumber.length doubleNumber doubleNumber.length i++ i++ i {

        		if (i < doubleNumber.length - 1) {

        			doubleNumber[i+1] = (doubleNumber[i] + doubleNumber[i+1]) / 2;
        		} else {

        			System.out.println(doubleNumber[doubleNumber.length - 1]);
        		}
            } {

        		if (i < doubleNumber.length - 1) {

        			doubleNumber[i+1] = (doubleNumber[i] + doubleNumber[i+1]) / 2;
        		} else {

        			System.out.println(doubleNumber[doubleNumber.length - 1]);
        		}
            } if (i < doubleNumber.length - 1) {

        			doubleNumber[i+1] = (doubleNumber[i] + doubleNumber[i+1]) / 2;
        		} else {

        			System.out.println(doubleNumber[doubleNumber.length - 1]);
        		} i < doubleNumber.length - 1 i doubleNumber.length - 1 doubleNumber.length doubleNumber doubleNumber.length 1 {

        			doubleNumber[i+1] = (doubleNumber[i] + doubleNumber[i+1]) / 2;
        		} doubleNumber[i+1] = (doubleNumber[i] + doubleNumber[i+1]) / 2 doubleNumber[i+1] doubleNumber i+1 i 1 (doubleNumber[i] + doubleNumber[i+1]) / 2 (doubleNumber[i] + doubleNumber[i+1]) doubleNumber[i] doubleNumber i doubleNumber[i+1] doubleNumber i+1 i 1 2 {

        			System.out.println(doubleNumber[doubleNumber.length - 1]);
        		} System.out.println(doubleNumber[doubleNumber.length - 1]) System.out.println System.out System System.out doubleNumber[doubleNumber.length - 1] doubleNumber doubleNumber.length - 1 doubleNumber.length doubleNumber doubleNumber.length 1 String[] args args public class Main {

	public static void main(String[] args) {

    	Scanner parameter = new Scanner(System.in);

    	String[] line1 = parameter.nextLine().split(" ");
        String[] line2 = parameter.nextLine().split(" ");

        double[] doubleNumber = new double[line2.length];

        for (int i = 0; i < line2.length; i++) {

        	doubleNumber[i] = Integer.parseInt(line2[i]);
        }

        Arrays.sort(doubleNumber);

        if (doubleNumber.length == 1) {

        	System.out.println(doubleNumber[0]);
        } else {

        	for (int i = 0; i < doubleNumber.length; i++) {

        		if (i < doubleNumber.length - 1) {

        			doubleNumber[i+1] = (doubleNumber[i] + doubleNumber[i+1]) / 2;
        		} else {

        			System.out.println(doubleNumber[doubleNumber.length - 1]);
        		}
            }
        }
    }
} public class Main {

	public static void main(String[] args) {

    	Scanner parameter = new Scanner(System.in);

    	String[] line1 = parameter.nextLine().split(" ");
        String[] line2 = parameter.nextLine().split(" ");

        double[] doubleNumber = new double[line2.length];

        for (int i = 0; i < line2.length; i++) {

        	doubleNumber[i] = Integer.parseInt(line2[i]);
        }

        Arrays.sort(doubleNumber);

        if (doubleNumber.length == 1) {

        	System.out.println(doubleNumber[0]);
        } else {

        	for (int i = 0; i < doubleNumber.length; i++) {

        		if (i < doubleNumber.length - 1) {

        			doubleNumber[i+1] = (doubleNumber[i] + doubleNumber[i+1]) / 2;
        		} else {

        			System.out.println(doubleNumber[doubleNumber.length - 1]);
        		}
            }
        }
    }
} Main
import java.util.Arrays;
import java.util.Scanner;


public class Main {

	public static void main(String[] args) {

    	Scanner parameter = new Scanner(System.in);

    	String[] line1 = parameter.nextLine().split(" ");
        String[] line2 = parameter.nextLine().split(" ");

        double[] doubleNumber = new double[line2.length];

        for (int i = 0; i < line2.length; i++) {

        	doubleNumber[i] = Integer.parseInt(line2[i]);
        }

        Arrays.sort(doubleNumber);

        if (doubleNumber.length == 1) {

        	System.out.println(doubleNumber[0]);
        } else {

        	for (int i = 0; i < doubleNumber.length; i++) {

        		if (i < doubleNumber.length - 1) {

        			doubleNumber[i+1] = (doubleNumber[i] + doubleNumber[i+1]) / 2;
        		} else {

        			System.out.println(doubleNumber[doubleNumber.length - 1]);
        		}
            }
        }
    }
}
