新人求助

#include<iostream>
using namespace std;
void Compare();
void Compare()
{
int x,y,z;
cout<<"Please input three numbers!"<<endl;
cin>>x,y,z;
int MaxN,MiddleN,MinN;
if(x>=y&&x>=z&&y>=z)
MiddleN=y;
MaxN=x;
MinN=z;
if(x>=y&&x>=z&&z>=y)
MaxN=x;
MiddleN=z;
MinN=y;
if(y>=z&&y>=x&&x>=z)
MaxN=y;
MiddleN=x;
MinN=z;
if(y>=z&&y>=x&&z>=x)
MaxN=y;
MiddleN=z;
MinN=x;
if(z>=x&&z>=y&&x>=y)
MaxN=z;
MiddleN=x;
MinN=y;
if(z>=x&&z>=y&&y>=x)
MaxN=z;
MiddleN=y;
MinN=x;
cout<<"输入数字依从大到小为："<<MaxN<<MiddleN<<MinN<<endl;
}
void main()
{
Compare();
}