#include<bits/stdc++.h>
using namespace std;
inline int read()
{
	int x=0,p=1;
	char ch=getchar();
	while(ch=='-')
	{
		p=-1;
		ch=getchar();
	}
	while(ch>='0' && ch<='9')
	{
		x=x*10+(ch-'0');
		ch=getchar();
	}
	return x*p;
}
int main()
{
     int m,n;
     m=read();n=read();
     double a[105]={0},b[105];
     for(int i=1;i<=m;i++)
     {
     	double maxx=INT_MIN;
     	double mini=INT_MAX;
     	for(int j=1;j<=n;j++)
     	{
     		a[j]=read();
     		maxx=max(maxx,a[j]);
     		mini=min(mini,a[j]);
     		b[i]+=a[j];
     	}
     	b[i]=(b[i]-maxx-mini)/(n-2);
     }
     sort(b,b+m+1);
     cout<<fixed<<setprecision(2)<<b[m-2];
     return 0;
}

仅仅过了样例