B

#include <bits/stdc++.h>

using namespace std;

#define ll     long long
#define _test   int _TEST; cin>>_TEST; while(_TEST--)

int main()
{
    _test
    {
        int n, k;
        cin>>n>>k;

        vector<int> a(n);
        for(auto &e: a)     cin>>e;

        vector<int> prev(k+1, -1);

        vector<multiset<int>> diff(k+1);

        for(int i=0; i<n; i++)
        {
            diff[a[i]].insert(i - prev[a[i]] - 1);
            prev[a[i]] = i;
        }

        for(int i=1; i<=k; i++)
            diff[i].insert(n - prev[i] - 1);

        int ans = 1e9;

        for(int i=1; i<=k; i++)
        {
            int x = *diff[i].rbegin();
            diff[i].erase(--diff[i].end());

            diff[i].insert(x/2);

            ans = min(ans, *diff[i].rbegin());
        }

        cout<<ans<<"\n";
    }
}