求救！

#include <bits/stdc++.h>
using namespace std;
int dis[3],Max;
int n,need;

int main()
{
	cin>>n;
	cin>>dis[1]>>dis[2]>>dis[3];
	sort(dis+1,dis+n+1);
	for(int i=2;i<=n;i++)
		need+=dis[i%2+1];
	cout<<need<<"\n";
}