#include<stdio.h>
int main() {
    int M, N;
    scanf("%d %d", &M, &N);
    if(M <=0 || N <=0){
        printf("Invalid Input");
        return 0;
    }
    float arr[100], temp;
    for(int i = 0; i < M; j++) {
        for(int j = i + 1;j < M; j++) {
            if(arr[i] > arr[j]){
                temp = arr[i];
                arr[i] = arr[j];
                arr[j] = temp;
            }
        }
    }
    float median;
    if(M % 2 == 1)
       median = (arr[M/2]);
    else
       median = (arr[M/2] + arr[M/2 - 1]) / 2;
       printf(" %.2f", median);
       return 0;
}