#include<bits/stdc++.h>

#pragma GCC optimize ("O3")
#pragma GCC optimize ("Ofast")
#pragma GCC optimize ("unroll-loops")

#define I first
#define II second
#define ver1 v*2+1
#define ver2 ver1+1
#define tm (tl+tr)/2
#define all(v) v.begin(),v.end()
#define pairrev(v) swap(v.first,v.second)
#define pairprint(v) cout<<v.first<<' '<<v.second<<endl;
#define accelerate ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0)

using namespace std;

typedef int ll;
typedef long double ld;
typedef pair<ll,ll> pairll;
typedef unsigned long long ull;

const ll DIM = 101;
const ll MOD = 1e9+7;

int main(){
    ll t;
    scanf("%d", &t);
    while(t --){
        ll n;
        scanf("%d", &n);
        double a[n+1];
        for (ll i=1; i<=n; i++) scanf("%lf", &a[i]);
        ll ans = n;
        if (n < 3) ans = 0;
        for (ll i=1; i<n; i++){
            for (ll j=i+1; j<=n; j++){
                ll cnt = 0;
                long double d = (a[j] - a[i]) / ((ld)(j - i));
                long double first = a[i] - ((ld)(i-1)) * ((a[j] - a[i]) / ((ld)(j - i)));
                for (ll k=1; k<=n; k++){
                    if (first + ((ld)(k-1))*d != a[k]) cnt ++;
                }
                ans = min(ans, cnt);
                if (ans == 0) break;
            }
            if (ans == 0) break;
        }
        cerr << "////";
        printf("%d\n", ans);
    }
    return 0;
}