#include <cstdio>
#include <iostream>
#include <string>
#include <sstream>
#include <cstring>
#include <stack>
#include <queue>
#include <algorithm>
#include <cmath>
#include <map>
#define PI acos(-1.0)
#define ms(a) memset(a,0,sizeof(a))
#define msp memset(mp,0,sizeof(mp))
#define msv memset(vis,0,sizeof(vis))
using namespace std;
//#define LOCAL
struct Node
{
    int no;
    double fen;
};
int cmp(Node a,Node b)
{
    return a.fen<b.fen;
}
int main()
{
#ifdef LOCAL
    freopen("in.txt", "r", stdin);
#endif // LOCAL
    ios::sync_with_stdio(false);
    vector<Node> v;
    int n;
    Node t;
    while(cin>>n&&n)
    {
        v.clear();
        for(int i=1;i<=n;i++)
        cin>>t.fen,t.no=i,v.push_back(t);
        sort(v.begin(),v.end(),cmp);
        double sum=0;
        for(int i=1;i<n-1;i++)sum+=v[i].fen;
        sum/=n-2;
        double minn=999;
        int mini=1;
        for(int i=1;i<n-1;i++)
        {
            if(abs(v[i].fen-sum)<minn)
            minn=abs(v[i].fen-sum),mini=i;
        }
        printf("%d\n",v[mini].no);
    }
    return 0;
}