#include <iostream>
using namespace std;
int a[200][30],t;
double b[20];
int main(){
	int n,m;
	scanf("%d %d",&n,&m);
	for(int i = 1;i <= n;i++){
		for(int j = 1;j <= m;j++){
			scanf("%d",&a[i][j]);
		}
		int max = -1,min = 12;
		for(int j = 1;j <= m;j++){
			if(a[i][j] > max){
				max = a[i][j];
			}
			if(a[i][j] < min){
				min = a[i][j];
			}
		}
		int h = 0;
		for(int j = 1;j <= m;j++){
			if(a[i][j] < max && a[i][j] > min){
				h += a[i][j];
			}
		}
		b[t++] = h / (m-2);
	}
	double max = 0.0;
	for(int i = 0;i < t;i++){
		if(b[i] > max){
			max = b[i];
		}
	}
	
	printf("%.2lf",max);
	return 0;
}

有问题！！！