#include<iostream>
#include<cstdio>
#include<cmath>

using namespace std;

int n,m;
int a[105][25];
double cnt,maxn;
int x[105] = {-1},y[105] = {99999}; 
int main(){
	scanf("%d %d", &n, &m);
	for(int i = 1; i <= n; i++){
		for(int j = 1; j <= m; j++){
			scanf("%d", &a[i][j]);
			x[i] = max(x[i], a[i][j]);
			y[i] = min(y[i], a[i][j]);
		}
	}
	for(int i = 1; i <= n; i++){
		for(int j = 1; j <= m; j++){
			cnt += a[i][j];
		}
		cnt -= x[i];
		cnt -= y[i];
		maxn = max(maxn, (cnt / (m - 2) * 1.0));
		cnt = 0;
	}
	printf("%.2lf", maxn);
	return 0;
}

逻辑都对啊，为什么拿不了满分？